Question: When would you use Monitor Node Health?

Answer: Monitor Node HealthNode Problem Detector is a daemon for monitoring and reporting about a node's health. You can run Node Problem Detector as a DaemonSet or as a standalone daemon. Node Problem Detector collects information about node problems from various daemons and reports these conditions to the API server as Node Conditions or as Events.To learn how to install and use Node Problem Detector, see Node Problem Detector project documentation.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesLimitationsNode Problem Detector uses the kernel log format for reporting kernel issues. To learn how to extend the kernel log format, see Add support for another log format.Enabling Node Problem DetectorSome cloud providers enable Node Problem Detector as an Addon. You can also enable Node Problem Detector with kubectl or by creating an Addon DaemonSet.Using kubectl to enable Node Problem Detectorkubectl provides the most flexible management of Node Problem Detector. You can overwrite the default configuration to fit it into your environment or to detect customized node problems. For example:Create a Node Problem Detector configuration similar to node-problem-detector.yaml:debug/node-problem-detector.yaml apiVersion: apps/v1 kind: DaemonSet metadata: name: node-problem-detector-v0.1 namespace: kube-system labels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" spec: selector: matchLabels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" template: metadata: labels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" spec: hostNetwork: true containers: - name: node-problem-detector image: registry.k8s.io/node-problem-detector:v0.1 securityContext: privileged: true resources: limits: cpu: "200m" memory: "100Mi" requests: cpu: "20m" memory: "20Mi" volumeMounts: - name: log mountPath: /log readOnly: true volumes: - name: log hostPath: path: /var/log/Note:You should verify that the system log directory is right for your operating system distribution.Start node problem detector with kubectl:kubectl apply -f https://k8s.io/examples/debug/node-problem-detector.yaml Using an Addon pod to enable Node Problem DetectorIf you are using a custom cluster bootstrap solution and don't need to overwrite the default configuration, you can leverage the Addon pod to further automate the deployment.Create node-problem-detector.yaml, and save the configuration in the Addon pod's directory /etc/kubernetes/addons/node-problem-detector on a control plane node.Overwrite the configurationThe default configu


Question: What are the benefits of Monitor Node Health?

Answer: Monitor Node HealthNode Problem Detector is a daemon for monitoring and reporting about a node's health. You can run Node Problem Detector as a DaemonSet or as a standalone daemon. Node Problem Detector collects information about node problems from various daemons and reports these conditions to the API server as Node Conditions or as Events.To learn how to install and use Node Problem Detector, see Node Problem Detector project documentation.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesLimitationsNode Problem Detector uses the kernel log format for reporting kernel issues. To learn how to extend the kernel log format, see Add support for another log format.Enabling Node Problem DetectorSome cloud providers enable Node Problem Detector as an Addon. You can also enable Node Problem Detector with kubectl or by creating an Addon DaemonSet.Using kubectl to enable Node Problem Detectorkubectl provides the most flexible management of Node Problem Detector. You can overwrite the default configuration to fit it into your environment or to detect customized node problems. For example:Create a Node Problem Detector configuration similar to node-problem-detector.yaml:debug/node-problem-detector.yaml apiVersion: apps/v1 kind: DaemonSet metadata: name: node-problem-detector-v0.1 namespace: kube-system labels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" spec: selector: matchLabels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" template: metadata: labels: k8s-app: node-problem-detector version: v0.1 kubernetes.io/cluster-service: "true" spec: hostNetwork: true containers: - name: node-problem-detector image: registry.k8s.io/node-problem-detector:v0.1 securityContext: privileged: true resources: limits: cpu: "200m" memory: "100Mi" requests: cpu: "20m" memory: "20Mi" volumeMounts: - name: log mountPath: /log readOnly: true volumes: - name: log hostPath: path: /var/log/Note:You should verify that the system log directory is right for your operating system distribution.Start node problem detector with kubectl:kubectl apply -f https://k8s.io/examples/debug/node-problem-detector.yaml Using an Addon pod to enable Node Problem DetectorIf you are using a custom cluster bootstrap solution and don't need to overwrite the default configuration, you can leverage the Addon pod to further automate the deployment.Create node-problem-detector.yaml, and save the configuration in the Addon pod's directory /etc/kubernetes/addons/node-problem-detector on a control plane node.Overwrite the configurationThe default configu


Question: What is Monitor Node Health?

Answer: N o d e   P r o b l e m   D e t e c t o r   i s   a   d a e m o n   f o r   m o n i t o r i n g   a n d   r e p o r t i n g   a b o u t   a   n o d e ' s   h e a l t h .   Y o u   c a n   r u n   N o d e   P r o b l e m   D e t e c t o r   a s   a   D a e m o n S e t   o r   a s   a   s t a n d a l o n e   d a e m o n .   N o d e   P r o b l e m   D e t e c t o r   c o l l e c t s   i n f o r m a t i o n   a b o u t   n o d e   p r o b l e m s   f r o m   v a r i o u s   d a e m o n s   a n d   r e p o r t s   t h e s e   c o n d i t i o n s   t o   t h e   A P I   s e r v e r   a s   N o d e   C o n d i t i o n s   o r   a s   E v e n t s .   T o   l e a r n   h o w   t o   i n s t a l l   a n d   u s e   N o d e   P r o b l e m   D e t e c t o r ,   s e e   N o d e   P r o b l e m   D e t e c t o r   p r o j e c t   d o c u m e n t a t i o n .


Question: What is Before you begin?

Answer: Y o u   n e e d   t o   h a v e   a   K u b e r n e t e s   c l u s t e r ,   a n d   t h e   k u b e c t l   c o m m a n d - l i n e   t o o l   m u s t   b e   c o n f i g u r e d   t o   c o m m u n i c a t e   w i t h   y o u r   c l u s t e r .   I t   i s   r e c o m m e n d e d   t o   r u n   t h i s   t u t o r i a l   o n   a   c l u s t e r   w i t h   a t   l e a s t   t w o   n o d e s   t h a t   a r e   n o t   a c t i n g   a s   c o n t r o l   p l a n e   h o s t s .   I f   y o u   d o   n o t   a l r e a d y   h a v e   a   c l u s t e r ,   y o u   c a n   c r e a t e   o n e   b y   u s i n g   m i n i k u b e   o r   y o u   c a n   u s e   o n e   o f   t h e s e   K u b e r n e t e s   p l a y g r o u n d s :   i x i m i u z   L a b s K i l l e r c o d a K o d e K l o u d P l a y   w i t h   K u b e r n e t e s


Question: What is Limitations?

Answer: N o d e   P r o b l e m   D e t e c t o r   u s e s   t h e   k e r n e l   l o g   f o r m a t   f o r   r e p o r t i n g   k e r n e l   i s s u e s .   T o   l e a r n   h o w   t o   e x t e n d   t h e   k e r n e l   l o g   f o r m a t ,   s e e   A d d   s u p p o r t   f o r   a n o t h e r   l o g   f o r m a t .


Question: What is Enabling Node Problem Detector?

Answer: S o m e   c l o u d   p r o v i d e r s   e n a b l e   N o d e   P r o b l e m   D e t e c t o r   a s   a n   A d d o n .   Y o u   c a n   a l s o   e n a b l e   N o d e   P r o b l e m   D e t e c t o r   w i t h   k u b e c t l   o r   b y   c r e a t i n g   a n   A d d o n   D a e m o n S e t .


Question: What is Using kubectl to enable Node Problem Detector?

Answer: k u b e c t l   p r o v i d e s   t h e   m o s t   f l e x i b l e   m a n a g e m e n t   o f   N o d e   P r o b l e m   D e t e c t o r .   Y o u   c a n   o v e r w r i t e   t h e   d e f a u l t   c o n f i g u r a t i o n   t o   f i t   i t   i n t o   y o u r   e n v i r o n m e n t   o r   t o   d e t e c t   c u s t o m i z e d   n o d e   p r o b l e m s .   F o r   e x a m p l e :   C r e a t e   a   N o d e   P r o b l e m   D e t e c t o r   c o n f i g u r a t i o n   s i m i l a r   t o   n o d e - p r o b l e m - d e t e c t o r . y a m l : d e b u g / n o d e - p r o b l e m - d e t e c t o r . y a m l   a p i V e r s i o n :   a p p s / v 1   k i n d :   D a e m o n S e t   m e t a d a t a :   n a m e :   n o d e - p r o b l e m - d e t e c t o r - v 0 . 1   n a m e s p a c e :   k u b e - s y s t e m   l a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   s p e c :   s e l e c t o r :   m a t c h L a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   t e m p l a t e :   m e t a d a t a :   l a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   s p e c :   h o s t N e t w o r k :   t r u e   c o n t a i n e r s :   -   n a m e :   n o d e - p r o b l e m - d e t e c t o r   i m a g e :   r e g i s t r y . k 8 s . i o / n o d e - p r o b l e m - d e t e c t o r : v 0 . 1   s e c u r i t y C o n t e x t :   p r i v i l e g e d :   t r u e   r e s o u r c e s :   l i m i t s :   c p u :   " 2 0 0 m "   m e m o r y :   " 1 0 0 M i "   r e q u e s t s :   c p u :   " 2 0 m "   m e m o r y :   " 2 0 M i "   v o l u m e M o u n t s :   -   n a m e :   l o g   m o u n t P a t h


Question: What is Note:?

Answer: S t a r t   n o d e   p r o b l e m   d e t e c t o r   w i t h   k u b e c t l :   k u b e c t l   a p p l y   - f   h t t p s : / / k 8 s . i o / e x a m p l e s / d e b u g / n o d e - p r o b l e m - d e t e c t o r . y a m l


Question: What is Using an Addon pod to enable Node Problem Detector?

Answer: I f   y o u   a r e   u s i n g   a   c u s t o m   c l u s t e r   b o o t s t r a p   s o l u t i o n   a n d   d o n ' t   n e e d   t o   o v e r w r i t e   t h e   d e f a u l t   c o n f i g u r a t i o n ,   y o u   c a n   l e v e r a g e   t h e   A d d o n   p o d   t o   f u r t h e r   a u t o m a t e   t h e   d e p l o y m e n t .   C r e a t e   n o d e - p r o b l e m - d e t e c t o r . y a m l ,   a n d   s a v e   t h e   c o n f i g u r a t i o n   i n   t h e   A d d o n   p o d ' s   d i r e c t o r y   / e t c / k u b e r n e t e s / a d d o n s / n o d e - p r o b l e m - d e t e c t o r   o n   a   c o n t r o l   p l a n e   n o d e .


Question: What is Overwrite the configuration?

Answer: T h e   d e f a u l t   c o n f i g u r a t i o n   i s   e m b e d d e d   w h e n   b u i l d i n g   t h e   D o c k e r   i m a g e   o f   N o d e   P r o b l e m   D e t e c t o r .   H o w e v e r ,   y o u   c a n   u s e   a   C o n f i g M a p   t o   o v e r w r i t e   t h e   c o n f i g u r a t i o n :   C h a n g e   t h e   c o n f i g u r a t i o n   f i l e s   i n   c o n f i g / C r e a t e   t h e   C o n f i g M a p   n o d e - p r o b l e m - d e t e c t o r - c o n f i g : k u b e c t l   c r e a t e   c o n f i g m a p   n o d e - p r o b l e m - d e t e c t o r - c o n f i g   - - f r o m - f i l e = c o n f i g /   C h a n g e   t h e   n o d e - p r o b l e m - d e t e c t o r . y a m l   t o   u s e   t h e   C o n f i g M a p : d e b u g / n o d e - p r o b l e m - d e t e c t o r - c o n f i g m a p . y a m l   a p i V e r s i o n :   a p p s / v 1   k i n d :   D a e m o n S e t   m e t a d a t a :   n a m e :   n o d e - p r o b l e m - d e t e c t o r - v 0 . 1   n a m e s p a c e :   k u b e - s y s t e m   l a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   s p e c :   s e l e c t o r :   m a t c h L a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   t e m p l a t e :   m e t a d a t a :   l a b e l s :   k 8 s - a p p :   n o d e - p r o b l e m - d e t e c t o r   v e r s i o n :   v 0 . 1   k u b e r n e t e s . i o / c l u s t e r - s e r v i c e :   " t r u e "   s p e c :   h o s t N e t w o r k :   t r u e   c o n t a i n e r s :   -   n a m e :   n o d e - p r o b l e m - d e t e c t o r   i m a g e :   r e g i s t r y . k 8 s . i o / n o d e - p r o b l e m - d e t e c t o r : v 0 . 1   s e c u r i t y C o n t e x t :   p r i v i l e g e d :   t r u e   r e s o u r c


Question: What is Note:?

Answer: O v e r w r i t i n g   a   c o n f i g u r a t i o n   i s   n o t   s u p p o r t e d   i f   a   N o d e   P r o b l e m   D e t e c t o r   r u n s   a s   a   c l u s t e r   A d d o n .   T h e   A d d o n   m a n a g e r   d o e s   n o t   s u p p o r t   C o n f i g M a p .


Question: What is Problem Daemons?

Answer: A   p r o b l e m   d a e m o n   i s   a   s u b - d a e m o n   o f   t h e   N o d e   P r o b l e m   D e t e c t o r .   I t   m o n i t o r s   s p e c i f i c   k i n d s   o f   n o d e   p r o b l e m s   a n d   r e p o r t s   t h e m   t o   t h e   N o d e   P r o b l e m   D e t e c t o r .   T h e r e   a r e   s e v e r a l   t y p e s   o f   s u p p o r t e d   p r o b l e m   d a e m o n s .   A   S y s t e m L o g M o n i t o r   t y p e   o f   d a e m o n   m o n i t o r s   t h e   s y s t e m   l o g s   a n d   r e p o r t s   p r o b l e m s   a n d   m e t r i c s   a c c o r d i n g   t o   p r e d e f i n e d   r u l e s .   Y o u   c a n   c u s t o m i z e   t h e   c o n f i g u r a t i o n s   f o r   d i f f e r e n t   l o g   s o u r c e s   s u c h   a s   f i l e l o g ,   k m s g ,   k e r n e l ,   a b r t ,   a n d   s y s t e m d . A   S y s t e m S t a t s M o n i t o r   t y p e   o f   d a e m o n   c o l l e c t s   v a r i o u s   h e a l t h - r e l a t e d   s y s t e m   s t a t s   a s   m e t r i c s .   Y o u   c a n   c u s t o m i z e   i t s   b e h a v i o r   b y   u p d a t i n g   i t s   c o n f i g u r a t i o n   f i l e . A   C u s t o m P l u g i n M o n i t o r   t y p e   o f   d a e m o n   i n v o k e s   a n d   c h e c k s   v a r i o u s   n o d e   p r o b l e m s   b y   r u n n i n g   u s e r - d e f i n e d   s c r i p t s .   Y o u   c a n   u s e   d i f f e r e n t   c u s t o m   p l u g i n   m o n i t o r s   t o   m o n i t o r   d i f f e r e n t   p r o b l e m s   a n d   c u s t o m i z e   t h e   d a e m o n   b e h a v i o r   b y   u p d a t i n g   t h e   c o n f i g u r a t i o n   f i l e . A   H e a l t h C h e c k e r   t y p e   o f   d a e m o n   c h e c k s   t h e   h e a l t h   o f   t h e   k u b e l e t   a n d   c o n t a i n e r   r u n t i m e   o n   a   n o d e .   A   S y s t e m L o g M o n i t o r   t y p e   o f   d a e m o n   m o n i t o r s   t h e


Question: What is Adding support for other log format?

Answer: T h e   s y s t e m   l o g   m o n i t o r   c u r r e n t l y   s u p p o r t s   f i l e - b a s e d   l o g s ,   j o u r n a l d ,   a n d   k m s g .   A d d i t i o n a l   s o u r c e s   c a n   b e   a d d e d   b y   i m p l e m e n t i n g   a   n e w   l o g   w a t c h e r .


Question: What is Adding custom plugin monitors?

Answer: Y o u   c a n   e x t e n d   t h e   N o d e   P r o b l e m   D e t e c t o r   t o   e x e c u t e   a n y   m o n i t o r   s c r i p t s   w r i t t e n   i n   a n y   l a n g u a g e   b y   d e v e l o p i n g   a   c u s t o m   p l u g i n .   T h e   m o n i t o r   s c r i p t s   m u s t   c o n f o r m   t o   t h e   p l u g i n   p r o t o c o l   i n   e x i t   c o d e   a n d   s t a n d a r d   o u t p u t .   F o r   m o r e   i n f o r m a t i o n ,   p l e a s e   r e f e r   t o   t h e   p l u g i n   i n t e r f a c e   p r o p o s a l .


Question: What is Exporter?

Answer: A n   e x p o r t e r   r e p o r t s   t h e   n o d e   p r o b l e m s   a n d / o r   m e t r i c s   t o   c e r t a i n   b a c k e n d s .   T h e   f o l l o w i n g   e x p o r t e r s   a r e   s u p p o r t e d :   K u b e r n e t e s   e x p o r t e r :   t h i s   e x p o r t e r   r e p o r t s   n o d e   p r o b l e m s   t o   t h e   K u b e r n e t e s   A P I   s e r v e r .   T e m p o r a r y   p r o b l e m s   a r e   r e p o r t e d   a s   E v e n t s   a n d   p e r m a n e n t   p r o b l e m s   a r e   r e p o r t e d   a s   N o d e   C o n d i t i o n s . P r o m e t h e u s   e x p o r t e r :   t h i s   e x p o r t e r   r e p o r t s   n o d e   p r o b l e m s   a n d   m e t r i c s   l o c a l l y   a s   P r o m e t h e u s   ( o r   O p e n M e t r i c s )   m e t r i c s .   Y o u   c a n   s p e c i f y   t h e   I P   a d d r e s s   a n d   p o r t   f o r   t h e   e x p o r t e r   u s i n g   c o m m a n d   l i n e   a r g u m e n t s . S t a c k d r i v e r   e x p o r t e r :   t h i s   e x p o r t e r   r e p o r t s   n o d e   p r o b l e m s   a n d   m e t r i c s   t o   t h e   S t a c k d r i v e r   M o n i t o r i n g   A P I .   T h e   e x p o r t i n g   b e h a v i o r   c a n   b e   c u s t o m i z e d   u s i n g   a   c o n f i g u r a t i o n   f i l e .   K u b e r n e t e s   e x p o r t e r :   t h i s   e x p o r t e r   r e p o r t s   n o d e   p r o b l e m s   t o   t h e   K u b e r n e t e s   A P I   s e r v e r .   T e m p o r a r y   p r o b l e m s   a r e   r e p o r t e d   a s   E v e n t s   a n d   p e r m a n e n t   p r o b l e m s   a r e   r e p o r t e d   a s   N o d e   C o n d i t i o n s .   P r o m e t h e u s   e x p o r t e r :   t h i s   e x p o r t e r   r e p o r t s   n o d e   p r o b l e m s   a n d   m e t r i c s   l o c a l l y   a s   P r o m e t h e u s   ( o r   O p e n M e t r i c s )   m e t r i c s .   Y o u   c a n   s p e c i f y   t h e   I P   a


Question: What is Recommendations and restrictions?

Answer: I t   i s   r e c o m m e n d e d   t o   r u n   t h e   N o d e   P r o b l e m   D e t e c t o r   i n   y o u r   c l u s t e r   t o   m o n i t o r   n o d e   h e a l t h .   W h e n   r u n n i n g   t h e   N o d e   P r o b l e m   D e t e c t o r ,   y o u   c a n   e x p e c t   e x t r a   r e s o u r c e   o v e r h e a d   o n   e a c h   n o d e .   U s u a l l y   t h i s   i s   f i n e ,   b e c a u s e :   T h e   k e r n e l   l o g   g r o w s   r e l a t i v e l y   s l o w l y . A   r e s o u r c e   l i m i t   i s   s e t   f o r   t h e   N o d e   P r o b l e m   D e t e c t o r . E v e n   u n d e r   h i g h   l o a d ,   t h e   r e s o u r c e   u s a g e   i s   a c c e p t a b l e .   F o r   m o r e   i n f o r m a t i o n ,   s e e   t h e   N o d e   P r o b l e m   D e t e c t o r   b e n c h m a r k   r e s u l t .


Question: What is Persistent Volumes?

Answer: Persistent VolumesThis document describes persistent volumes in Kubernetes. Familiarity with volumes, StorageClasses and VolumeAttributesClasses is suggested.IntroductionManaging storage is a distinct problem from managing compute instances. The PersistentVolume subsystem provides an API for users and administrators that abstracts details of how storage is provided from how it is consumed. To do this, we introduce two new API resources: PersistentVolume and PersistentVolumeClaim.A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically provisioned using Storage Classes. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims can request specific size and access modes (e.g., they can be mounted ReadWriteOnce, ReadOnlyMany, ReadWriteMany, or ReadWriteOncePod, see AccessModes).While PersistentVolumeClaims allow a user to consume abstract storage resources, it is common that users need PersistentVolumes with varying properties, such as performance, for different problems. Cluster administrators need to be able to offer a variety of PersistentVolumes that differ in more ways than size and access modes, without exposing users to the details of how those volumes are implemented. For these needs, there is the StorageClass resource.See the detailed walkthrough with working examples.Lifecycle of a volume and claimPVs are resources in the cluster. PVCs are requests for those resources and also act as claim checks to the resource. The interaction between PVs and PVCs follows this lifecycle:ProvisioningThere are two ways PVs may be provisioned: statically or dynamically.StaticA cluster administrator creates a number of PVs. They carry the details of the real storage, which is available for use by cluster users. They exist in the Kubernetes API and are available for consumption.DynamicWhen none of the static PVs the administrator created match a user's PersistentVolumeClaim, the cluster may try to dynamically provision a volume specially for the PVC. This provisioning is based on StorageClasses: the PVC must request a storage class and the administrator must have created and configured that class for dynamic provisioning to occur. Claims that request the class "" effectively disable dynamic provisioning for themselves.To enable dynamic storage provisioning based on storage class, the cluster administrator needs to enable the DefaultStorageClass admission controller on the API server. This can be done, for example, by ensu


Question: How does Persistent Volumes work?

Answer: Persistent VolumesThis document describes persistent volumes in Kubernetes. Familiarity with volumes, StorageClasses and VolumeAttributesClasses is suggested.IntroductionManaging storage is a distinct problem from managing compute instances. The PersistentVolume subsystem provides an API for users and administrators that abstracts details of how storage is provided from how it is consumed. To do this, we introduce two new API resources: PersistentVolume and PersistentVolumeClaim.A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically provisioned using Storage Classes. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims can request specific size and access modes (e.g., they can be mounted ReadWriteOnce, ReadOnlyMany, ReadWriteMany, or ReadWriteOncePod, see AccessModes).While PersistentVolumeClaims allow a user to consume abstract storage resources, it is common that users need PersistentVolumes with varying properties, such as performance, for different problems. Cluster administrators need to be able to offer a variety of PersistentVolumes that differ in more ways than size and access modes, without exposing users to the details of how those volumes are implemented. For these needs, there is the StorageClass resource.See the detailed walkthrough with working examples.Lifecycle of a volume and claimPVs are resources in the cluster. PVCs are requests for those resources and also act as claim checks to the resource. The interaction between PVs and PVCs follows this lifecycle:ProvisioningThere are two ways PVs may be provisioned: statically or dynamically.StaticA cluster administrator creates a number of PVs. They carry the details of the real storage, which is available for use by cluster users. They exist in the Kubernetes API and are available for consumption.DynamicWhen none of the static PVs the administrator created match a user's PersistentVolumeClaim, the cluster may try to dynamically provision a volume specially for the PVC. This provisioning is based on StorageClasses: the PVC must request a storage class and the administrator must have created and configured that class for dynamic provisioning to occur. Claims that request the class "" effectively disable dynamic provisioning for themselves.To enable dynamic storage provisioning based on storage class, the cluster administrator needs to enable the DefaultStorageClass admission controller on the API server. This can be done, for example, by ensu


Question: When would you use Persistent Volumes?

Answer: Persistent VolumesThis document describes persistent volumes in Kubernetes. Familiarity with volumes, StorageClasses and VolumeAttributesClasses is suggested.IntroductionManaging storage is a distinct problem from managing compute instances. The PersistentVolume subsystem provides an API for users and administrators that abstracts details of how storage is provided from how it is consumed. To do this, we introduce two new API resources: PersistentVolume and PersistentVolumeClaim.A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically provisioned using Storage Classes. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims can request specific size and access modes (e.g., they can be mounted ReadWriteOnce, ReadOnlyMany, ReadWriteMany, or ReadWriteOncePod, see AccessModes).While PersistentVolumeClaims allow a user to consume abstract storage resources, it is common that users need PersistentVolumes with varying properties, such as performance, for different problems. Cluster administrators need to be able to offer a variety of PersistentVolumes that differ in more ways than size and access modes, without exposing users to the details of how those volumes are implemented. For these needs, there is the StorageClass resource.See the detailed walkthrough with working examples.Lifecycle of a volume and claimPVs are resources in the cluster. PVCs are requests for those resources and also act as claim checks to the resource. The interaction between PVs and PVCs follows this lifecycle:ProvisioningThere are two ways PVs may be provisioned: statically or dynamically.StaticA cluster administrator creates a number of PVs. They carry the details of the real storage, which is available for use by cluster users. They exist in the Kubernetes API and are available for consumption.DynamicWhen none of the static PVs the administrator created match a user's PersistentVolumeClaim, the cluster may try to dynamically provision a volume specially for the PVC. This provisioning is based on StorageClasses: the PVC must request a storage class and the administrator must have created and configured that class for dynamic provisioning to occur. Claims that request the class "" effectively disable dynamic provisioning for themselves.To enable dynamic storage provisioning based on storage class, the cluster administrator needs to enable the DefaultStorageClass admission controller on the API server. This can be done, for example, by ensu


Question: What are the benefits of Persistent Volumes?

Answer: Persistent VolumesThis document describes persistent volumes in Kubernetes. Familiarity with volumes, StorageClasses and VolumeAttributesClasses is suggested.IntroductionManaging storage is a distinct problem from managing compute instances. The PersistentVolume subsystem provides an API for users and administrators that abstracts details of how storage is provided from how it is consumed. To do this, we introduce two new API resources: PersistentVolume and PersistentVolumeClaim.A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically provisioned using Storage Classes. It is a resource in the cluster just like a node is a cluster resource. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV. This API object captures the details of the implementation of the storage, be that NFS, iSCSI, or a cloud-provider-specific storage system.A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory). Claims can request specific size and access modes (e.g., they can be mounted ReadWriteOnce, ReadOnlyMany, ReadWriteMany, or ReadWriteOncePod, see AccessModes).While PersistentVolumeClaims allow a user to consume abstract storage resources, it is common that users need PersistentVolumes with varying properties, such as performance, for different problems. Cluster administrators need to be able to offer a variety of PersistentVolumes that differ in more ways than size and access modes, without exposing users to the details of how those volumes are implemented. For these needs, there is the StorageClass resource.See the detailed walkthrough with working examples.Lifecycle of a volume and claimPVs are resources in the cluster. PVCs are requests for those resources and also act as claim checks to the resource. The interaction between PVs and PVCs follows this lifecycle:ProvisioningThere are two ways PVs may be provisioned: statically or dynamically.StaticA cluster administrator creates a number of PVs. They carry the details of the real storage, which is available for use by cluster users. They exist in the Kubernetes API and are available for consumption.DynamicWhen none of the static PVs the administrator created match a user's PersistentVolumeClaim, the cluster may try to dynamically provision a volume specially for the PVC. This provisioning is based on StorageClasses: the PVC must request a storage class and the administrator must have created and configured that class for dynamic provisioning to occur. Claims that request the class "" effectively disable dynamic provisioning for themselves.To enable dynamic storage provisioning based on storage class, the cluster administrator needs to enable the DefaultStorageClass admission controller on the API server. This can be done, for example, by ensu


Question: What is Persistent Volumes?

Answer: T h i s   d o c u m e n t   d e s c r i b e s   p e r s i s t e n t   v o l u m e s   i n   K u b e r n e t e s .   F a m i l i a r i t y   w i t h   v o l u m e s ,   S t o r a g e C l a s s e s   a n d   V o l u m e A t t r i b u t e s C l a s s e s   i s   s u g g e s t e d .


Question: What is Introduction?

Answer: M a n a g i n g   s t o r a g e   i s   a   d i s t i n c t   p r o b l e m   f r o m   m a n a g i n g   c o m p u t e   i n s t a n c e s .   T h e   P e r s i s t e n t V o l u m e   s u b s y s t e m   p r o v i d e s   a n   A P I   f o r   u s e r s   a n d   a d m i n i s t r a t o r s   t h a t   a b s t r a c t s   d e t a i l s   o f   h o w   s t o r a g e   i s   p r o v i d e d   f r o m   h o w   i t   i s   c o n s u m e d .   T o   d o   t h i s ,   w e   i n t r o d u c e   t w o   n e w   A P I   r e s o u r c e s :   P e r s i s t e n t V o l u m e   a n d   P e r s i s t e n t V o l u m e C l a i m .   A   P e r s i s t e n t V o l u m e   ( P V )   i s   a   p i e c e   o f   s t o r a g e   i n   t h e   c l u s t e r   t h a t   h a s   b e e n   p r o v i s i o n e d   b y   a n   a d m i n i s t r a t o r   o r   d y n a m i c a l l y   p r o v i s i o n e d   u s i n g   S t o r a g e   C l a s s e s .   I t   i s   a   r e s o u r c e   i n   t h e   c l u s t e r   j u s t   l i k e   a   n o d e   i s   a   c l u s t e r   r e s o u r c e .   P V s   a r e   v o l u m e   p l u g i n s   l i k e   V o l u m e s ,   b u t   h a v e   a   l i f e c y c l e   i n d e p e n d e n t   o f   a n y   i n d i v i d u a l   P o d   t h a t   u s e s   t h e   P V .   T h i s   A P I   o b j e c t   c a p t u r e s   t h e   d e t a i l s   o f   t h e   i m p l e m e n t a t i o n   o f   t h e   s t o r a g e ,   b e   t h a t   N F S ,   i S C S I ,   o r   a   c l o u d - p r o v i d e r - s p e c i f i c   s t o r a g e   s y s t e m .   A   P e r s i s t e n t V o l u m e C l a i m   ( P V C )   i s   a   r e q u e s t   f o r   s t o r a g e   b y   a   u s e r .   I t   i s   s i m i l a r   t o   a   P o d .   P o d s   c o n s u m e   n o d e   r e s o u r c e s   a n d   P V C s   c o n s u m e   P V   r e s o u r c e s .   P o d s   c a n   r e q u e s t   s p e c i f i c   l e v e l s   o f   r e s o u r c e s   ( C P U   a n d   M e


Question: What is Lifecycle of a volume and claim?

Answer: P V s   a r e   r e s o u r c e s   i n   t h e   c l u s t e r .   P V C s   a r e   r e q u e s t s   f o r   t h o s e   r e s o u r c e s   a n d   a l s o   a c t   a s   c l a i m   c h e c k s   t o   t h e   r e s o u r c e .   T h e   i n t e r a c t i o n   b e t w e e n   P V s   a n d   P V C s   f o l l o w s   t h i s   l i f e c y c l e :


Question: What is Provisioning?

Answer: T h e r e   a r e   t w o   w a y s   P V s   m a y   b e   p r o v i s i o n e d :   s t a t i c a l l y   o r   d y n a m i c a l l y .


Question: What is Static?

Answer: A   c l u s t e r   a d m i n i s t r a t o r   c r e a t e s   a   n u m b e r   o f   P V s .   T h e y   c a r r y   t h e   d e t a i l s   o f   t h e   r e a l   s t o r a g e ,   w h i c h   i s   a v a i l a b l e   f o r   u s e   b y   c l u s t e r   u s e r s .   T h e y   e x i s t   i n   t h e   K u b e r n e t e s   A P I   a n d   a r e   a v a i l a b l e   f o r   c o n s u m p t i o n .


Question: What is Dynamic?

Answer: W h e n   n o n e   o f   t h e   s t a t i c   P V s   t h e   a d m i n i s t r a t o r   c r e a t e d   m a t c h   a   u s e r ' s   P e r s i s t e n t V o l u m e C l a i m ,   t h e   c l u s t e r   m a y   t r y   t o   d y n a m i c a l l y   p r o v i s i o n   a   v o l u m e   s p e c i a l l y   f o r   t h e   P V C .   T h i s   p r o v i s i o n i n g   i s   b a s e d   o n   S t o r a g e C l a s s e s :   t h e   P V C   m u s t   r e q u e s t   a   s t o r a g e   c l a s s   a n d   t h e   a d m i n i s t r a t o r   m u s t   h a v e   c r e a t e d   a n d   c o n f i g u r e d   t h a t   c l a s s   f o r   d y n a m i c   p r o v i s i o n i n g   t o   o c c u r .   C l a i m s   t h a t   r e q u e s t   t h e   c l a s s   " "   e f f e c t i v e l y   d i s a b l e   d y n a m i c   p r o v i s i o n i n g   f o r   t h e m s e l v e s .   T o   e n a b l e   d y n a m i c   s t o r a g e   p r o v i s i o n i n g   b a s e d   o n   s t o r a g e   c l a s s ,   t h e   c l u s t e r   a d m i n i s t r a t o r   n e e d s   t o   e n a b l e   t h e   D e f a u l t S t o r a g e C l a s s   a d m i s s i o n   c o n t r o l l e r   o n   t h e   A P I   s e r v e r .   T h i s   c a n   b e   d o n e ,   f o r   e x a m p l e ,   b y   e n s u r i n g   t h a t   D e f a u l t S t o r a g e C l a s s   i s   a m o n g   t h e   c o m m a - d e l i m i t e d ,   o r d e r e d   l i s t   o f   v a l u e s   f o r   t h e   - - e n a b l e - a d m i s s i o n - p l u g i n s   f l a g   o f   t h e   A P I   s e r v e r   c o m p o n e n t .   F o r   m o r e   i n f o r m a t i o n   o n   A P I   s e r v e r   c o m m a n d - l i n e   f l a g s ,   c h e c k   k u b e - a p i s e r v e r   d o c u m e n t a t i o n .


Question: What is Binding?

Answer: A   u s e r   c r e a t e s ,   o r   i n   t h e   c a s e   o f   d y n a m i c   p r o v i s i o n i n g ,   h a s   a l r e a d y   c r e a t e d ,   a   P e r s i s t e n t V o l u m e C l a i m   w i t h   a   s p e c i f i c   a m o u n t   o f   s t o r a g e   r e q u e s t e d   a n d   w i t h   c e r t a i n   a c c e s s   m o d e s .   A   c o n t r o l   l o o p   i n   t h e   c o n t r o l   p l a n e   w a t c h e s   f o r   n e w   P V C s ,   f i n d s   a   m a t c h i n g   P V   ( i f   p o s s i b l e ) ,   a n d   b i n d s   t h e m   t o g e t h e r .   I f   a   P V   w a s   d y n a m i c a l l y   p r o v i s i o n e d   f o r   a   n e w   P V C ,   t h e   l o o p   w i l l   a l w a y s   b i n d   t h a t   P V   t o   t h e   P V C .   O t h e r w i s e ,   t h e   u s e r   w i l l   a l w a y s   g e t   a t   l e a s t   w h a t   t h e y   a s k e d   f o r ,   b u t   t h e   v o l u m e   m a y   b e   i n   e x c e s s   o f   w h a t   w a s   r e q u e s t e d .   O n c e   b o u n d ,   P e r s i s t e n t V o l u m e C l a i m   b i n d s   a r e   e x c l u s i v e ,   r e g a r d l e s s   o f   h o w   t h e y   w e r e   b o u n d .   A   P V C   t o   P V   b i n d i n g   i s   a   o n e - t o - o n e   m a p p i n g ,   u s i n g   a   C l a i m R e f   w h i c h   i s   a   b i - d i r e c t i o n a l   b i n d i n g   b e t w e e n   t h e   P e r s i s t e n t V o l u m e   a n d   t h e   P e r s i s t e n t V o l u m e C l a i m .   C l a i m s   w i l l   r e m a i n   u n b o u n d   i n d e f i n i t e l y   i f   a   m a t c h i n g   v o l u m e   d o e s   n o t   e x i s t .   C l a i m s   w i l l   b e   b o u n d   a s   m a t c h i n g   v o l u m e s   b e c o m e   a v a i l a b l e .   F o r   e x a m p l e ,   a   c l u s t e r   p r o v i s i o n e d   w i t h   m a n y   5 0 G i   P V s   w o u l d   n o t   m a t c h   a   P V C   r e q u e s t i n g   1 0 0 G i .   T h e   P V C   c a n


Question: What is Using?

Answer: P o d s   u s e   c l a i m s   a s   v o l u m e s .   T h e   c l u s t e r   i n s p e c t s   t h e   c l a i m   t o   f i n d   t h e   b o u n d   v o l u m e   a n d   m o u n t s   t h a t   v o l u m e   f o r   a   P o d .   F o r   v o l u m e s   t h a t   s u p p o r t   m u l t i p l e   a c c e s s   m o d e s ,   t h e   u s e r   s p e c i f i e s   w h i c h   m o d e   i s   d e s i r e d   w h e n   u s i n g   t h e i r   c l a i m   a s   a   v o l u m e   i n   a   P o d .   O n c e   a   u s e r   h a s   a   c l a i m   a n d   t h a t   c l a i m   i s   b o u n d ,   t h e   b o u n d   P V   b e l o n g s   t o   t h e   u s e r   f o r   a s   l o n g   a s   t h e y   n e e d   i t .   U s e r s   s c h e d u l e   P o d s   a n d   a c c e s s   t h e i r   c l a i m e d   P V s   b y   i n c l u d i n g   a   p e r s i s t e n t V o l u m e C l a i m   s e c t i o n   i n   a   P o d ' s   v o l u m e s   b l o c k .   S e e   C l a i m s   A s   V o l u m e s   f o r   m o r e   d e t a i l s   o n   t h i s .


Question: What is Storage Object in Use Protection?

Answer: T h e   p u r p o s e   o f   t h e   S t o r a g e   O b j e c t   i n   U s e   P r o t e c t i o n   f e a t u r e   i s   t o   e n s u r e   t h a t   P e r s i s t e n t V o l u m e C l a i m s   ( P V C s )   i n   a c t i v e   u s e   b y   a   P o d   a n d   P e r s i s t e n t V o l u m e   ( P V s )   t h a t   a r e   b o u n d   t o   P V C s   a r e   n o t   r e m o v e d   f r o m   t h e   s y s t e m ,   a s   t h i s   m a y   r e s u l t   i n   d a t a   l o s s .


Question: What is Note:?

Answer: I f   a   u s e r   d e l e t e s   a   P V C   i n   a c t i v e   u s e   b y   a   P o d ,   t h e   P V C   i s   n o t   r e m o v e d   i m m e d i a t e l y .   P V C   r e m o v a l   i s   p o s t p o n e d   u n t i l   t h e   P V C   i s   n o   l o n g e r   a c t i v e l y   u s e d   b y   a n y   P o d s .   A l s o ,   i f   a n   a d m i n   d e l e t e s   a   P V   t h a t   i s   b o u n d   t o   a   P V C ,   t h e   P V   i s   n o t   r e m o v e d   i m m e d i a t e l y .   P V   r e m o v a l   i s   p o s t p o n e d   u n t i l   t h e   P V   i s   n o   l o n g e r   b o u n d   t o   a   P V C .   Y o u   c a n   s e e   t h a t   a   P V C   i s   p r o t e c t e d   w h e n   t h e   P V C ' s   s t a t u s   i s   T e r m i n a t i n g   a n d   t h e   F i n a l i z e r s   l i s t   i n c l u d e s   k u b e r n e t e s . i o / p v c - p r o t e c t i o n :   k u b e c t l   d e s c r i b e   p v c   h o s t p a t h   N a m e :   h o s t p a t h   N a m e s p a c e :   d e f a u l t   S t o r a g e C l a s s :   e x a m p l e - h o s t p a t h   S t a t u s :   T e r m i n a t i n g   V o l u m e :   L a b e l s :   < n o n e >   A n n o t a t i o n s :   v o l u m e . b e t a . k u b e r n e t e s . i o / s t o r a g e - c l a s s = e x a m p l e - h o s t p a t h   v o l u m e . b e t a . k u b e r n e t e s . i o / s t o r a g e - p r o v i s i o n e r = e x a m p l e . c o m / h o s t p a t h   F i n a l i z e r s :   [ k u b e r n e t e s . i o / p v c - p r o t e c t i o n ]   . . .   Y o u   c a n   s e e   t h a t   a   P V   i s   p r o t e c t e d   w h e n   t h e   P V ' s   s t a t u s   i s   T e r m i n a t i n g   a n d   t h e   F i n a l i z e r s   l i s t   i n c l u d e s   k u b e r n e t e s . i o / p v - p r o t e c t i o n   t o o :   k u b e c t l   d e s c r i b e   p v   t a s k - p v - v o l u m e   N a m e :   t a s k - p v - v o l u m e   L a b e l s :   t y p e = l o c a l   A n n o t a t i o n s


Question: What is Reclaiming?

Answer: W h e n   a   u s e r   i s   d o n e   w i t h   t h e i r   v o l u m e ,   t h e y   c a n   d e l e t e   t h e   P V C   o b j e c t s   f r o m   t h e   A P I   t h a t   a l l o w s   r e c l a m a t i o n   o f   t h e   r e s o u r c e .   T h e   r e c l a i m   p o l i c y   f o r   a   P e r s i s t e n t V o l u m e   t e l l s   t h e   c l u s t e r   w h a t   t o   d o   w i t h   t h e   v o l u m e   a f t e r   i t   h a s   b e e n   r e l e a s e d   o f   i t s   c l a i m .   C u r r e n t l y ,   v o l u m e s   c a n   e i t h e r   b e   R e t a i n e d ,   R e c y c l e d ,   o r   D e l e t e d .


Question: What is Retain?

Answer: T h e   R e t a i n   r e c l a i m   p o l i c y   a l l o w s   f o r   m a n u a l   r e c l a m a t i o n   o f   t h e   r e s o u r c e .   W h e n   t h e   P e r s i s t e n t V o l u m e C l a i m   i s   d e l e t e d ,   t h e   P e r s i s t e n t V o l u m e   s t i l l   e x i s t s   a n d   t h e   v o l u m e   i s   c o n s i d e r e d   " r e l e a s e d " .   B u t   i t   i s   n o t   y e t   a v a i l a b l e   f o r   a n o t h e r   c l a i m   b e c a u s e   t h e   p r e v i o u s   c l a i m a n t ' s   d a t a   r e m a i n s   o n   t h e   v o l u m e .   A n   a d m i n i s t r a t o r   c a n   m a n u a l l y   r e c l a i m   t h e   v o l u m e   w i t h   t h e   f o l l o w i n g   s t e p s .   D e l e t e   t h e   P e r s i s t e n t V o l u m e .   T h e   a s s o c i a t e d   s t o r a g e   a s s e t   i n   e x t e r n a l   i n f r a s t r u c t u r e   s t i l l   e x i s t s   a f t e r   t h e   P V   i s   d e l e t e d . M a n u a l l y   c l e a n   u p   t h e   d a t a   o n   t h e   a s s o c i a t e d   s t o r a g e   a s s e t   a c c o r d i n g l y . M a n u a l l y   d e l e t e   t h e   a s s o c i a t e d   s t o r a g e   a s s e t .   I f   y o u   w a n t   t o   r e u s e   t h e   s a m e   s t o r a g e   a s s e t ,   c r e a t e   a   n e w   P e r s i s t e n t V o l u m e   w i t h   t h e   s a m e   s t o r a g e   a s s e t   d e f i n i t i o n .


Question: What is Delete?

Answer: F o r   v o l u m e   p l u g i n s   t h a t   s u p p o r t   t h e   D e l e t e   r e c l a i m   p o l i c y ,   d e l e t i o n   r e m o v e s   b o t h   t h e   P e r s i s t e n t V o l u m e   o b j e c t   f r o m   K u b e r n e t e s ,   a s   w e l l   a s   t h e   a s s o c i a t e d   s t o r a g e   a s s e t   i n   t h e   e x t e r n a l   i n f r a s t r u c t u r e .   V o l u m e s   t h a t   w e r e   d y n a m i c a l l y   p r o v i s i o n e d   i n h e r i t   t h e   r e c l a i m   p o l i c y   o f   t h e i r   S t o r a g e C l a s s ,   w h i c h   d e f a u l t s   t o   D e l e t e .   T h e   a d m i n i s t r a t o r   s h o u l d   c o n f i g u r e   t h e   S t o r a g e C l a s s   a c c o r d i n g   t o   u s e r s '   e x p e c t a t i o n s ;   o t h e r w i s e ,   t h e   P V   m u s t   b e   e d i t e d   o r   p a t c h e d   a f t e r   i t   i s   c r e a t e d .   S e e   C h a n g e   t h e   R e c l a i m   P o l i c y   o f   a   P e r s i s t e n t V o l u m e .


Question: What is Warning:?

Answer: I f   s u p p o r t e d   b y   t h e   u n d e r l y i n g   v o l u m e   p l u g i n ,   t h e   R e c y c l e   r e c l a i m   p o l i c y   p e r f o r m s   a   b a s i c   s c r u b   ( r m   - r f   / t h e v o l u m e / * )   o n   t h e   v o l u m e   a n d   m a k e s   i t   a v a i l a b l e   a g a i n   f o r   a   n e w   c l a i m .   H o w e v e r ,   a n   a d m i n i s t r a t o r   c a n   c o n f i g u r e   a   c u s t o m   r e c y c l e r   P o d   t e m p l a t e   u s i n g   t h e   K u b e r n e t e s   c o n t r o l l e r   m a n a g e r   c o m m a n d   l i n e   a r g u m e n t s   a s   d e s c r i b e d   i n   t h e   r e f e r e n c e .   T h e   c u s t o m   r e c y c l e r   P o d   t e m p l a t e   m u s t   c o n t a i n   a   v o l u m e s   s p e c i f i c a t i o n ,   a s   s h o w n   i n   t h e   e x a m p l e   b e l o w :   a p i V e r s i o n :   v 1   k i n d :   P o d   m e t a d a t a :   n a m e :   p v - r e c y c l e r   n a m e s p a c e :   d e f a u l t   s p e c :   r e s t a r t P o l i c y :   N e v e r   v o l u m e s :   -   n a m e :   v o l   h o s t P a t h :   p a t h :   / a n y / p a t h / i t / w i l l / b e / r e p l a c e d   c o n t a i n e r s :   -   n a m e :   p v - r e c y c l e r   i m a g e :   " r e g i s t r y . k 8 s . i o / b u s y b o x "   c o m m a n d :   [ " / b i n / s h " ,   " - c " ,   " t e s t   - e   / s c r u b   & &   r m   - r f   / s c r u b / . . ? *   / s c r u b / . [ ! . ] *   / s c r u b / *   & &   t e s t   - z   \ " $ ( l s   - A   / s c r u b ) \ "   | |   e x i t   1 " ]   v o l u m e M o u n t s :   -   n a m e :   v o l   m o u n t P a t h :   / s c r u b   H o w e v e r ,   t h e   p a r t i c u l a r   p a t h   s p e c i f i e d   i n   t h e   c u s t o m   r e c y c l e r   P o d   t e m p l a t e   i n   t h e   v o l u m e s   p a r t   i s   r e p l a c e d   w i t h   t h e   p a r t i c u l a r   p a t h   o f   t h e   v o l u m e   t h a


Question: What is PersistentVolume deletion protection finalizer?

Answer: F i n a l i z e r s   c a n   b e   a d d e d   o n   a   P e r s i s t e n t V o l u m e   t o   e n s u r e   t h a t   P e r s i s t e n t V o l u m e s   h a v i n g   D e l e t e   r e c l a i m   p o l i c y   a r e   d e l e t e d   o n l y   a f t e r   t h e   b a c k i n g   s t o r a g e   a r e   d e l e t e d .   T h e   f i n a l i z e r   e x t e r n a l - p r o v i s i o n e r . v o l u m e . k u b e r n e t e s . i o / f i n a l i z e r ( i n t r o d u c e d   i n   v 1 . 3 1 )   i s   a d d e d   t o   b o t h   d y n a m i c a l l y   p r o v i s i o n e d   a n d   s t a t i c a l l y   p r o v i s i o n e d   C S I   v o l u m e s .   T h e   f i n a l i z e r   k u b e r n e t e s . i o / p v - c o n t r o l l e r ( i n t r o d u c e d   i n   v 1 . 3 1 )   i s   a d d e d   t o   d y n a m i c a l l y   p r o v i s i o n e d   i n - t r e e   p l u g i n   v o l u m e s   a n d   s k i p p e d   f o r   s t a t i c a l l y   p r o v i s i o n e d   i n - t r e e   p l u g i n   v o l u m e s .   T h e   f o l l o w i n g   i s   a n   e x a m p l e   o f   d y n a m i c a l l y   p r o v i s i o n e d   i n - t r e e   p l u g i n   v o l u m e :   k u b e c t l   d e s c r i b e   p v   p v c - 7 4 a 4 9 8 d 6 - 3 9 2 9 - 4 7 e 8 - 8 c 0 2 - 0 7 8 c 1 e c e 4 d 7 8   N a m e :   p v c - 7 4 a 4 9 8 d 6 - 3 9 2 9 - 4 7 e 8 - 8 c 0 2 - 0 7 8 c 1 e c e 4 d 7 8   L a b e l s :   < n o n e >   A n n o t a t i o n s :   k u b e r n e t e s . i o / c r e a t e d b y :   v s p h e r e - v o l u m e - d y n a m i c - p r o v i s i o n e r   p v . k u b e r n e t e s . i o / b o u n d - b y - c o n t r o l l e r :   y e s   p v . k u b e r n e t e s . i o / p r o v i s i o n e d - b y :   k u b e r n e t e s . i o / v s p h e r e - v o l u m e   F i n a l i z e r s :   [ k u b e r n e t e s . i o / p v - p r o t e c t i o n   k u b e r n e t e s . i o / p v - c o n t r o l l e r ]   S t o r a g e C l a s s :   v c p - s c   S t a t u s :   B o u n d


Question: What is Reserving a PersistentVolume?

Answer: T h e   c o n t r o l   p l a n e   c a n   b i n d   P e r s i s t e n t V o l u m e C l a i m s   t o   m a t c h i n g   P e r s i s t e n t V o l u m e s   i n   t h e   c l u s t e r .   H o w e v e r ,   i f   y o u   w a n t   a   P V C   t o   b i n d   t o   a   s p e c i f i c   P V ,   y o u   n e e d   t o   p r e - b i n d   t h e m .   B y   s p e c i f y i n g   a   P e r s i s t e n t V o l u m e   i n   a   P e r s i s t e n t V o l u m e C l a i m ,   y o u   d e c l a r e   a   b i n d i n g   b e t w e e n   t h a t   s p e c i f i c   P V   a n d   P V C .   I f   t h e   P e r s i s t e n t V o l u m e   e x i s t s   a n d   h a s   n o t   r e s e r v e d   P e r s i s t e n t V o l u m e C l a i m s   t h r o u g h   i t s   c l a i m R e f   f i e l d ,   t h e n   t h e   P e r s i s t e n t V o l u m e   a n d   P e r s i s t e n t V o l u m e C l a i m   w i l l   b e   b o u n d .   T h e   b i n d i n g   h a p p e n s   r e g a r d l e s s   o f   s o m e   v o l u m e   m a t c h i n g   c r i t e r i a ,   i n c l u d i n g   n o d e   a f f i n i t y .   T h e   c o n t r o l   p l a n e   s t i l l   c h e c k s   t h a t   s t o r a g e   c l a s s ,   a c c e s s   m o d e s ,   a n d   r e q u e s t e d   s t o r a g e   s i z e   a r e   v a l i d .   a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   f o o - p v c   n a m e s p a c e :   f o o   s p e c :   s t o r a g e C l a s s N a m e :   " "   #   E m p t y   s t r i n g   m u s t   b e   e x p l i c i t l y   s e t   o t h e r w i s e   d e f a u l t   S t o r a g e C l a s s   w i l l   b e   s e t   v o l u m e N a m e :   f o o - p v   . . .   T h i s   m e t h o d   d o e s   n o t   g u a r a n t e e   a n y   b i n d i n g   p r i v i l e g e s   t o   t h e   P e r s i s t e n t V o l u m e .   I f   o t h e r   P e r s i s t e n t V o l u m e C l a i m s   c o u l d   u s e   t h e   P V   t h a


Question: What is Expanding Persistent Volumes Claims?

Answer: S u p p o r t   f o r   e x p a n d i n g   P e r s i s t e n t V o l u m e C l a i m s   ( P V C s )   i s   e n a b l e d   b y   d e f a u l t .   Y o u   c a n   e x p a n d   t h e   f o l l o w i n g   t y p e s   o f   v o l u m e s :   c s i   ( i n c l u d i n g   s o m e   C S I   m i g r a t e d   v o l m e   t y p e s ) f l e x V o l u m e   ( d e p r e c a t e d ) p o r t w o r x V o l u m e   ( d e p r e c a t e d )   Y o u   c a n   o n l y   e x p a n d   a   P V C   i f   i t s   s t o r a g e   c l a s s ' s   a l l o w V o l u m e E x p a n s i o n   f i e l d   i s   s e t   t o   t r u e .   a p i V e r s i o n :   s t o r a g e . k 8 s . i o / v 1   k i n d :   S t o r a g e C l a s s   m e t a d a t a :   n a m e :   e x a m p l e - v o l - d e f a u l t   p r o v i s i o n e r :   v e n d o r - n a m e . e x a m p l e / m a g i c s t o r a g e   p a r a m e t e r s :   r e s t u r l :   " h t t p : / / 1 9 2 . 1 6 8 . 1 0 . 1 0 0 : 8 0 8 0 "   r e s t u s e r :   " "   s e c r e t N a m e s p a c e :   " "   s e c r e t N a m e :   " "   a l l o w V o l u m e E x p a n s i o n :   t r u e   T o   r e q u e s t   a   l a r g e r   v o l u m e   f o r   a   P V C ,   e d i t   t h e   P V C   o b j e c t   a n d   s p e c i f y   a   l a r g e r   s i z e .   T h i s   t r i g g e r s   e x p a n s i o n   o f   t h e   v o l u m e   t h a t   b a c k s   t h e   u n d e r l y i n g   P e r s i s t e n t V o l u m e .   A   n e w   P e r s i s t e n t V o l u m e   i s   n e v e r   c r e a t e d   t o   s a t i s f y   t h e   c l a i m .   I n s t e a d ,   a n   e x i s t i n g   v o l u m e   i s   r e s i z e d .


Question: What is CSI Volume expansion?

Answer: S u p p o r t   f o r   e x p a n d i n g   C S I   v o l u m e s   i s   e n a b l e d   b y   d e f a u l t   b u t   i t   a l s o   r e q u i r e s   a   s p e c i f i c   C S I   d r i v e r   t o   s u p p o r t   v o l u m e   e x p a n s i o n .   R e f e r   t o   d o c u m e n t a t i o n   o f   t h e   s p e c i f i c   C S I   d r i v e r   f o r   m o r e   i n f o r m a t i o n .


Question: What is Resizing a volume containing a file system?

Answer: Y o u   c a n   o n l y   r e s i z e   v o l u m e s   c o n t a i n i n g   a   f i l e   s y s t e m   i f   t h e   f i l e   s y s t e m   i s   X F S ,   E x t 3 ,   o r   E x t 4 .   W h e n   a   v o l u m e   c o n t a i n s   a   f i l e   s y s t e m ,   t h e   f i l e   s y s t e m   i s   o n l y   r e s i z e d   w h e n   a   n e w   P o d   i s   u s i n g   t h e   P e r s i s t e n t V o l u m e C l a i m   i n   R e a d W r i t e   m o d e .   F i l e   s y s t e m   e x p a n s i o n   i s   e i t h e r   d o n e   w h e n   a   P o d   i s   s t a r t i n g   u p   o r   w h e n   a   P o d   i s   r u n n i n g   a n d   t h e   u n d e r l y i n g   f i l e   s y s t e m   s u p p o r t s   o n l i n e   e x p a n s i o n .   F l e x V o l u m e s   ( d e p r e c a t e d   s i n c e   K u b e r n e t e s   v 1 . 2 3 )   a l l o w   r e s i z e   i f   t h e   d r i v e r   i s   c o n f i g u r e d   w i t h   t h e   R e q u i r e s F S R e s i z e   c a p a b i l i t y   t o   t r u e .   T h e   F l e x V o l u m e   c a n   b e   r e s i z e d   o n   P o d   r e s t a r t .


Question: What is Resizing an in-use PersistentVolumeClaim?

Answer: I n   t h i s   c a s e ,   y o u   d o n ' t   n e e d   t o   d e l e t e   a n d   r e c r e a t e   a   P o d   o r   d e p l o y m e n t   t h a t   i s   u s i n g   a n   e x i s t i n g   P V C .   A n y   i n - u s e   P V C   a u t o m a t i c a l l y   b e c o m e s   a v a i l a b l e   t o   i t s   P o d   a s   s o o n   a s   i t s   f i l e   s y s t e m   h a s   b e e n   e x p a n d e d .   T h i s   f e a t u r e   h a s   n o   e f f e c t   o n   P V C s   t h a t   a r e   n o t   i n   u s e   b y   a   P o d   o r   d e p l o y m e n t .   Y o u   m u s t   c r e a t e   a   P o d   t h a t   u s e s   t h e   P V C   b e f o r e   t h e   e x p a n s i o n   c a n   c o m p l e t e .   S i m i l a r   t o   o t h e r   v o l u m e   t y p e s   -   F l e x V o l u m e   v o l u m e s   c a n   a l s o   b e   e x p a n d e d   w h e n   i n - u s e   b y   a   P o d .


Question: What is Recovering from Failure when Expanding Volumes?

Answer: I f   a   u s e r   s p e c i f i e s   a   n e w   s i z e   t h a t   i s   t o o   b i g   t o   b e   s a t i s f i e d   b y   u n d e r l y i n g   s t o r a g e   s y s t e m ,   e x p a n s i o n   o f   P V C   w i l l   b e   c o n t i n u o u s l y   r e t r i e d   u n t i l   u s e r   o r   c l u s t e r   a d m i n i s t r a t o r   t a k e s   s o m e   a c t i o n .   T h i s   c a n   b e   u n d e s i r a b l e   a n d   h e n c e   K u b e r n e t e s   p r o v i d e s   f o l l o w i n g   m e t h o d s   o f   r e c o v e r i n g   f r o m   s u c h   f a i l u r e s .   I f   e x p a n d i n g   u n d e r l y i n g   s t o r a g e   f a i l s ,   t h e   c l u s t e r   a d m i n i s t r a t o r   c a n   m a n u a l l y   r e c o v e r   t h e   P e r s i s t e n t   V o l u m e   C l a i m   ( P V C )   s t a t e   a n d   c a n c e l   t h e   r e s i z e   r e q u e s t s .   O t h e r w i s e ,   t h e   r e s i z e   r e q u e s t s   a r e   c o n t i n u o u s l y   r e t r i e d   b y   t h e   c o n t r o l l e r   w i t h o u t   a d m i n i s t r a t o r   i n t e r v e n t i o n . M a r k   t h e   P e r s i s t e n t V o l u m e ( P V )   t h a t   i s   b o u n d   t o   t h e   P e r s i s t e n t V o l u m e C l a i m ( P V C )   w i t h   R e t a i n   r e c l a i m   p o l i c y . D e l e t e   t h e   P V C .   S i n c e   P V   h a s   R e t a i n   r e c l a i m   p o l i c y   -   w e   w i l l   n o t   l o s e   a n y   d a t a   w h e n   w e   r e c r e a t e   t h e   P V C . D e l e t e   t h e   c l a i m R e f   e n t r y   f r o m   P V   s p e c s ,   s o   a s   n e w   P V C   c a n   b i n d   t o   i t .   T h i s   s h o u l d   m a k e   t h e   P V   A v a i l a b l e . R e - c r e a t e   t h e   P V C   w i t h   s m a l l e r   s i z e   t h a n   P V   a n d   s e t   v o l u m e N a m e   f i e l d   o f   t h e   P V C   t o   t h e   n a m e   o f   t h e   P V .   T h i s   s h o u l d   b i n d


Question: What is Types of Persistent Volumes?

Answer: P e r s i s t e n t V o l u m e   t y p e s   a r e   i m p l e m e n t e d   a s   p l u g i n s .   K u b e r n e t e s   c u r r e n t l y   s u p p o r t s   t h e   f o l l o w i n g   p l u g i n s :   c s i   -   C o n t a i n e r   S t o r a g e   I n t e r f a c e   ( C S I ) f c   -   F i b r e   C h a n n e l   ( F C )   s t o r a g e h o s t P a t h   -   H o s t P a t h   v o l u m e   ( f o r   s i n g l e   n o d e   t e s t i n g   o n l y ;   W I L L   N O T   W O R K   i n   a   m u l t i - n o d e   c l u s t e r ;   c o n s i d e r   u s i n g   l o c a l   v o l u m e   i n s t e a d ) i s c s i   -   i S C S I   ( S C S I   o v e r   I P )   s t o r a g e l o c a l   -   l o c a l   s t o r a g e   d e v i c e s   m o u n t e d   o n   n o d e s . n f s   -   N e t w o r k   F i l e   S y s t e m   ( N F S )   s t o r a g e   T h e   f o l l o w i n g   t y p e s   o f   P e r s i s t e n t V o l u m e   a r e   d e p r e c a t e d   b u t   s t i l l   a v a i l a b l e .   I f   y o u   a r e   u s i n g   t h e s e   v o l u m e   t y p e s   e x c e p t   f o r   f l e x V o l u m e ,   c e p h f s   a n d   r b d ,   p l e a s e   i n s t a l l   c o r r e s p o n d i n g   C S I   d r i v e r s .   a w s E l a s t i c B l o c k S t o r e   -   A W S   E l a s t i c   B l o c k   S t o r e   ( E B S )   ( m i g r a t i o n   o n   b y   d e f a u l t   s t a r t i n g   v 1 . 2 3 ) a z u r e D i s k   -   A z u r e   D i s k   ( m i g r a t i o n   o n   b y   d e f a u l t   s t a r t i n g   v 1 . 2 3 ) a z u r e F i l e   -   A z u r e   F i l e   ( m i g r a t i o n   o n   b y   d e f a u l t   s t a r t i n g   v 1 . 2 4 ) c i n d e r   -   C i n d e r   ( O p e n S t a c k   b l o c k   s t o r a g e )   ( m i g r a t i o n   o n   b y   d e f a u l t   s t a r t i n g   v 1 . 2 1 ) f l e x V o l u m e   -   F l e x V o l u m e   ( d e p r e c a t e d   s t a r t i n g   v 1 . 2 3 ,   n o   m i g r a t i o n   p l a n   a n d   n o


Question: What is Persistent Volumes?

Answer: E a c h   P V   c o n t a i n s   a   s p e c   a n d   s t a t u s ,   w h i c h   i s   t h e   s p e c i f i c a t i o n   a n d   s t a t u s   o f   t h e   v o l u m e .   T h e   n a m e   o f   a   P e r s i s t e n t V o l u m e   o b j e c t   m u s t   b e   a   v a l i d   D N S   s u b d o m a i n   n a m e .   a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e   m e t a d a t a :   n a m e :   p v 0 0 0 3   s p e c :   c a p a c i t y :   s t o r a g e :   5 G i   v o l u m e M o d e :   F i l e s y s t e m   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   p e r s i s t e n t V o l u m e R e c l a i m P o l i c y :   R e c y c l e   s t o r a g e C l a s s N a m e :   s l o w   m o u n t O p t i o n s :   -   h a r d   -   n f s v e r s = 4 . 1   n f s :   p a t h :   / t m p   s e r v e r :   1 7 2 . 1 7 . 0 . 2


Question: What is Capacity?

Answer: G e n e r a l l y ,   a   P V   w i l l   h a v e   a   s p e c i f i c   s t o r a g e   c a p a c i t y .   T h i s   i s   s e t   u s i n g   t h e   P V ' s   c a p a c i t y   a t t r i b u t e   w h i c h   i s   a   Q u a n t i t y   v a l u e .   C u r r e n t l y ,   s t o r a g e   s i z e   i s   t h e   o n l y   r e s o u r c e   t h a t   c a n   b e   s e t   o r   r e q u e s t e d .   F u t u r e   a t t r i b u t e s   m a y   i n c l u d e   I O P S ,   t h r o u g h p u t ,   e t c .


Question: What is Volume Mode?

Answer: K u b e r n e t e s   s u p p o r t s   t w o   v o l u m e M o d e s   o f   P e r s i s t e n t V o l u m e s :   F i l e s y s t e m   a n d   B l o c k .   v o l u m e M o d e   i s   a n   o p t i o n a l   A P I   p a r a m e t e r .   F i l e s y s t e m   i s   t h e   d e f a u l t   m o d e   u s e d   w h e n   v o l u m e M o d e   p a r a m e t e r   i s   o m i t t e d .   A   v o l u m e   w i t h   v o l u m e M o d e :   F i l e s y s t e m   i s   m o u n t e d   i n t o   P o d s   i n t o   a   d i r e c t o r y .   I f   t h e   v o l u m e   i s   b a c k e d   b y   a   b l o c k   d e v i c e   a n d   t h e   d e v i c e   i s   e m p t y ,   K u b e r n e t e s   c r e a t e s   a   f i l e s y s t e m   o n   t h e   d e v i c e   b e f o r e   m o u n t i n g   i t   f o r   t h e   f i r s t   t i m e .   Y o u   c a n   s e t   t h e   v a l u e   o f   v o l u m e M o d e   t o   B l o c k   t o   u s e   a   v o l u m e   a s   a   r a w   b l o c k   d e v i c e .   S u c h   v o l u m e   i s   p r e s e n t e d   i n t o   a   P o d   a s   a   b l o c k   d e v i c e ,   w i t h o u t   a n y   f i l e s y s t e m   o n   i t .   T h i s   m o d e   i s   u s e f u l   t o   p r o v i d e   a   P o d   t h e   f a s t e s t   p o s s i b l e   w a y   t o   a c c e s s   a   v o l u m e ,   w i t h o u t   a n y   f i l e s y s t e m   l a y e r   b e t w e e n   t h e   P o d   a n d   t h e   v o l u m e .   O n   t h e   o t h e r   h a n d ,   t h e   a p p l i c a t i o n   r u n n i n g   i n   t h e   P o d   m u s t   k n o w   h o w   t o   h a n d l e   a   r a w   b l o c k   d e v i c e .   S e e   R a w   B l o c k   V o l u m e   S u p p o r t   f o r   a n   e x a m p l e   o n   h o w   t o   u s e   a   v o l u m e   w i t h   v o l u m e M o d e :   B l o c k   i n   a   P o d .


Question: What is Access Modes?

Answer: A   P e r s i s t e n t V o l u m e   c a n   b e   m o u n t e d   o n   a   h o s t   i n   a n y   w a y   s u p p o r t e d   b y   t h e   r e s o u r c e   p r o v i d e r .   A s   s h o w n   i n   t h e   t a b l e   b e l o w ,   p r o v i d e r s   w i l l   h a v e   d i f f e r e n t   c a p a b i l i t i e s   a n d   e a c h   P V ' s   a c c e s s   m o d e s   a r e   s e t   t o   t h e   s p e c i f i c   m o d e s   s u p p o r t e d   b y   t h a t   p a r t i c u l a r   v o l u m e .   F o r   e x a m p l e ,   N F S   c a n   s u p p o r t   m u l t i p l e   r e a d / w r i t e   c l i e n t s ,   b u t   a   s p e c i f i c   N F S   P V   m i g h t   b e   e x p o r t e d   o n   t h e   s e r v e r   a s   r e a d - o n l y .   E a c h   P V   g e t s   i t s   o w n   s e t   o f   a c c e s s   m o d e s   d e s c r i b i n g   t h a t   s p e c i f i c   P V ' s   c a p a b i l i t i e s .   T h e   a c c e s s   m o d e s   a r e :


Question: What is Note:?

Answer: T h e   R e a d W r i t e O n c e P o d   a c c e s s   m o d e   i s   o n l y   s u p p o r t e d   f o r   C S I   v o l u m e s   a n d   K u b e r n e t e s   v e r s i o n   1 . 2 2 + .   T o   u s e   t h i s   f e a t u r e   y o u   w i l l   n e e d   t o   u p d a t e   t h e   f o l l o w i n g   C S I   s i d e c a r s   t o   t h e s e   v e r s i o n s   o r   g r e a t e r :   c s i - p r o v i s i o n e r : v 3 . 0 . 0 + c s i - a t t a c h e r : v 3 . 3 . 0 + c s i - r e s i z e r : v 1 . 3 . 0 +   I n   t h e   C L I ,   t h e   a c c e s s   m o d e s   a r e   a b b r e v i a t e d   t o :   R W O   -   R e a d W r i t e O n c e R O X   -   R e a d O n l y M a n y R W X   -   R e a d W r i t e M a n y R W O P   -   R e a d W r i t e O n c e P o d


Question: What is Note:?

Answer: I m p o r t a n t !   A   v o l u m e   c a n   o n l y   b e   m o u n t e d   u s i n g   o n e   a c c e s s   m o d e   a t   a   t i m e ,   e v e n   i f   i t   s u p p o r t s   m a n y .


Question: What is Class?

Answer: A   P V   c a n   h a v e   a   c l a s s ,   w h i c h   i s   s p e c i f i e d   b y   s e t t i n g   t h e   s t o r a g e C l a s s N a m e   a t t r i b u t e   t o   t h e   n a m e   o f   a   S t o r a g e C l a s s .   A   P V   o f   a   p a r t i c u l a r   c l a s s   c a n   o n l y   b e   b o u n d   t o   P V C s   r e q u e s t i n g   t h a t   c l a s s .   A   P V   w i t h   n o   s t o r a g e C l a s s N a m e   h a s   n o   c l a s s   a n d   c a n   o n l y   b e   b o u n d   t o   P V C s   t h a t   r e q u e s t   n o   p a r t i c u l a r   c l a s s .   I n   t h e   p a s t ,   t h e   a n n o t a t i o n   v o l u m e . b e t a . k u b e r n e t e s . i o / s t o r a g e - c l a s s   w a s   u s e d   i n s t e a d   o f   t h e   s t o r a g e C l a s s N a m e   a t t r i b u t e .   T h i s   a n n o t a t i o n   i s   s t i l l   w o r k i n g ;   h o w e v e r ,   i t   w i l l   b e c o m e   f u l l y   d e p r e c a t e d   i n   a   f u t u r e   K u b e r n e t e s   r e l e a s e .


Question: What is Reclaim Policy?

Answer: C u r r e n t   r e c l a i m   p o l i c i e s   a r e :   R e t a i n   - -   m a n u a l   r e c l a m a t i o n R e c y c l e   - -   b a s i c   s c r u b   ( r m   - r f   / t h e v o l u m e / * ) D e l e t e   - -   d e l e t e   t h e   v o l u m e   F o r   K u b e r n e t e s   1 . 3 4 ,   o n l y   n f s   a n d   h o s t P a t h   v o l u m e   t y p e s   s u p p o r t   r e c y c l i n g .


Question: What is Mount Options?

Answer: A   K u b e r n e t e s   a d m i n i s t r a t o r   c a n   s p e c i f y   a d d i t i o n a l   m o u n t   o p t i o n s   f o r   w h e n   a   P e r s i s t e n t   V o l u m e   i s   m o u n t e d   o n   a   n o d e .


Question: What is Note:?

Answer: T h e   f o l l o w i n g   v o l u m e   t y p e s   s u p p o r t   m o u n t   o p t i o n s :   c s i   ( i n c l u d i n g   C S I   m i g r a t e d   v o l u m e   t y p e s ) i s c s i n f s   M o u n t   o p t i o n s   a r e   n o t   v a l i d a t e d .   I f   a   m o u n t   o p t i o n   i s   i n v a l i d ,   t h e   m o u n t   f a i l s .   I n   t h e   p a s t ,   t h e   a n n o t a t i o n   v o l u m e . b e t a . k u b e r n e t e s . i o / m o u n t - o p t i o n s   w a s   u s e d   i n s t e a d   o f   t h e   m o u n t O p t i o n s   a t t r i b u t e .   T h i s   a n n o t a t i o n   i s   s t i l l   w o r k i n g ;   h o w e v e r ,   i t   w i l l   b e c o m e   f u l l y   d e p r e c a t e d   i n   a   f u t u r e   K u b e r n e t e s   r e l e a s e .


Question: What is Note:?

Answer: A   P V   c a n   s p e c i f y   n o d e   a f f i n i t y   t o   d e f i n e   c o n s t r a i n t s   t h a t   l i m i t   w h a t   n o d e s   t h i s   v o l u m e   c a n   b e   a c c e s s e d   f r o m .   P o d s   t h a t   u s e   a   P V   w i l l   o n l y   b e   s c h e d u l e d   t o   n o d e s   t h a t   a r e   s e l e c t e d   b y   t h e   n o d e   a f f i n i t y .   T o   s p e c i f y   n o d e   a f f i n i t y ,   s e t   n o d e A f f i n i t y   i n   t h e   . s p e c   o f   a   P V .   T h e   P e r s i s t e n t V o l u m e   A P I   r e f e r e n c e   h a s   m o r e   d e t a i l s   o n   t h i s   f i e l d .


Question: What is Phase?

Answer: A   P e r s i s t e n t V o l u m e   w i l l   b e   i n   o n e   o f   t h e   f o l l o w i n g   p h a s e s :   Y o u   c a n   s e e   t h e   n a m e   o f   t h e   P V C   b o u n d   t o   t h e   P V   u s i n g   k u b e c t l   d e s c r i b e   p e r s i s t e n t v o l u m e   < n a m e > .


Question: What is Phase transition timestamp?

Answer: T h e   . s t a t u s   f i e l d   f o r   a   P e r s i s t e n t V o l u m e   c a n   i n c l u d e   a n   a l p h a   l a s t P h a s e T r a n s i t i o n T i m e   f i e l d .   T h i s   f i e l d   r e c o r d s   t h e   t i m e s t a m p   o f   w h e n   t h e   v o l u m e   l a s t   t r a n s i t i o n e d   i t s   p h a s e .   F o r   n e w l y   c r e a t e d   v o l u m e s   t h e   p h a s e   i s   s e t   t o   P e n d i n g   a n d   l a s t P h a s e T r a n s i t i o n T i m e   i s   s e t   t o   t h e   c u r r e n t   t i m e .


Question: What is PersistentVolumeClaims?

Answer: E a c h   P V C   c o n t a i n s   a   s p e c   a n d   s t a t u s ,   w h i c h   i s   t h e   s p e c i f i c a t i o n   a n d   s t a t u s   o f   t h e   c l a i m .   T h e   n a m e   o f   a   P e r s i s t e n t V o l u m e C l a i m   o b j e c t   m u s t   b e   a   v a l i d   D N S   s u b d o m a i n   n a m e .   a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   m y c l a i m   s p e c :   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   v o l u m e M o d e :   F i l e s y s t e m   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   8 G i   s t o r a g e C l a s s N a m e :   s l o w   s e l e c t o r :   m a t c h L a b e l s :   r e l e a s e :   " s t a b l e "   m a t c h E x p r e s s i o n s :   -   { k e y :   e n v i r o n m e n t ,   o p e r a t o r :   I n ,   v a l u e s :   [ d e v ] }


Question: What is Access Modes?

Answer: C l a i m s   u s e   t h e   s a m e   c o n v e n t i o n s   a s   v o l u m e s   w h e n   r e q u e s t i n g   s t o r a g e   w i t h   s p e c i f i c   a c c e s s   m o d e s .


Question: What is Volume Modes?

Answer: C l a i m s   u s e   t h e   s a m e   c o n v e n t i o n   a s   v o l u m e s   t o   i n d i c a t e   t h e   c o n s u m p t i o n   o f   t h e   v o l u m e   a s   e i t h e r   a   f i l e s y s t e m   o r   b l o c k   d e v i c e .


Question: What is Volume Name?

Answer: C l a i m s   c a n   u s e   t h e   v o l u m e N a m e   f i e l d   t o   e x p l i c i t l y   b i n d   t o   a   s p e c i f i c   P e r s i s t e n t V o l u m e .   Y o u   c a n   a l s o   l e a v e   v o l u m e N a m e   u n s e t ,   i n d i c a t i n g   t h a t   y o u ' d   l i k e   K u b e r n e t e s   t o   s e t   u p   a   n e w   P e r s i s t e n t V o l u m e   t h a t   m a t c h e s   t h e   c l a i m .   I f   t h e   s p e c i f i e d   P V   i s   a l r e a d y   b o u n d   t o   a n o t h e r   P V C ,   t h e   b i n d i n g   w i l l   b e   s t u c k   i n   a   p e n d i n g   s t a t e .


Question: What is Resources?

Answer: C l a i m s ,   l i k e   P o d s ,   c a n   r e q u e s t   s p e c i f i c   q u a n t i t i e s   o f   a   r e s o u r c e .   I n   t h i s   c a s e ,   t h e   r e q u e s t   i s   f o r   s t o r a g e .   T h e   s a m e   r e s o u r c e   m o d e l   a p p l i e s   t o   b o t h   v o l u m e s   a n d   c l a i m s .


Question: What is Selector?

Answer: C l a i m s   c a n   s p e c i f y   a   l a b e l   s e l e c t o r   t o   f u r t h e r   f i l t e r   t h e   s e t   o f   v o l u m e s .   O n l y   t h e   v o l u m e s   w h o s e   l a b e l s   m a t c h   t h e   s e l e c t o r   c a n   b e   b o u n d   t o   t h e   c l a i m .   T h e   s e l e c t o r   c a n   c o n s i s t   o f   t w o   f i e l d s :   m a t c h L a b e l s   -   t h e   v o l u m e   m u s t   h a v e   a   l a b e l   w i t h   t h i s   v a l u e m a t c h E x p r e s s i o n s   -   a   l i s t   o f   r e q u i r e m e n t s   m a d e   b y   s p e c i f y i n g   k e y ,   l i s t   o f   v a l u e s ,   a n d   o p e r a t o r   t h a t   r e l a t e s   t h e   k e y   a n d   v a l u e s .   V a l i d   o p e r a t o r s   i n c l u d e   I n ,   N o t I n ,   E x i s t s ,   a n d   D o e s N o t E x i s t .   A l l   o f   t h e   r e q u i r e m e n t s ,   f r o m   b o t h   m a t c h L a b e l s   a n d   m a t c h E x p r e s s i o n s ,   a r e   A N D e d   t o g e t h e r   –   t h e y   m u s t   a l l   b e   s a t i s f i e d   i n   o r d e r   t o   m a t c h .


Question: What is Class?

Answer: A   c l a i m   c a n   r e q u e s t   a   p a r t i c u l a r   c l a s s   b y   s p e c i f y i n g   t h e   n a m e   o f   a   S t o r a g e C l a s s   u s i n g   t h e   a t t r i b u t e   s t o r a g e C l a s s N a m e .   O n l y   P V s   o f   t h e   r e q u e s t e d   c l a s s ,   o n e s   w i t h   t h e   s a m e   s t o r a g e C l a s s N a m e   a s   t h e   P V C ,   c a n   b e   b o u n d   t o   t h e   P V C .   P V C s   d o n ' t   n e c e s s a r i l y   h a v e   t o   r e q u e s t   a   c l a s s .   A   P V C   w i t h   i t s   s t o r a g e C l a s s N a m e   s e t   e q u a l   t o   " "   i s   a l w a y s   i n t e r p r e t e d   t o   b e   r e q u e s t i n g   a   P V   w i t h   n o   c l a s s ,   s o   i t   c a n   o n l y   b e   b o u n d   t o   P V s   w i t h   n o   c l a s s   ( n o   a n n o t a t i o n   o r   o n e   s e t   e q u a l   t o   " " ) .   A   P V C   w i t h   n o   s t o r a g e C l a s s N a m e   i s   n o t   q u i t e   t h e   s a m e   a n d   i s   t r e a t e d   d i f f e r e n t l y   b y   t h e   c l u s t e r ,   d e p e n d i n g   o n   w h e t h e r   t h e   D e f a u l t S t o r a g e C l a s s   a d m i s s i o n   p l u g i n   i s   t u r n e d   o n .   I f   t h e   a d m i s s i o n   p l u g i n   i s   t u r n e d   o n ,   t h e   a d m i n i s t r a t o r   m a y   s p e c i f y   a   d e f a u l t   S t o r a g e C l a s s .   A l l   P V C s   t h a t   h a v e   n o   s t o r a g e C l a s s N a m e   c a n   b e   b o u n d   o n l y   t o   P V s   o f   t h a t   d e f a u l t .   S p e c i f y i n g   a   d e f a u l t   S t o r a g e C l a s s   i s   d o n e   b y   s e t t i n g   t h e   a n n o t a t i o n   s t o r a g e c l a s s . k u b e r n e t e s . i o / i s - d e f a u l t - c l a s s   e q u a l   t o   t r u e   i n   a   S t o r a g e C l a s s   o b j e c t .   I f   t h e   a d m i n i s t r a t o r   d o e s   n o t   s p e c i f y   a


Question: What is Note:?

Answer: I n   t h e   p a s t ,   t h e   a n n o t a t i o n   v o l u m e . b e t a . k u b e r n e t e s . i o / s t o r a g e - c l a s s   w a s   u s e d   i n s t e a d   o f   s t o r a g e C l a s s N a m e   a t t r i b u t e .   T h i s   a n n o t a t i o n   i s   s t i l l   w o r k i n g ;   h o w e v e r ,   i t   w o n ' t   b e   s u p p o r t e d   i n   a   f u t u r e   K u b e r n e t e s   r e l e a s e .


Question: What is Retroactive default StorageClass assignment?

Answer: Y o u   c a n   c r e a t e   a   P e r s i s t e n t V o l u m e C l a i m   w i t h o u t   s p e c i f y i n g   a   s t o r a g e C l a s s N a m e   f o r   t h e   n e w   P V C ,   a n d   y o u   c a n   d o   s o   e v e n   w h e n   n o   d e f a u l t   S t o r a g e C l a s s   e x i s t s   i n   y o u r   c l u s t e r .   I n   t h i s   c a s e ,   t h e   n e w   P V C   c r e a t e s   a s   y o u   d e f i n e d   i t ,   a n d   t h e   s t o r a g e C l a s s N a m e   o f   t h a t   P V C   r e m a i n s   u n s e t   u n t i l   d e f a u l t   b e c o m e s   a v a i l a b l e .   W h e n   a   d e f a u l t   S t o r a g e C l a s s   b e c o m e s   a v a i l a b l e ,   t h e   c o n t r o l   p l a n e   i d e n t i f i e s   a n y   e x i s t i n g   P V C s   w i t h o u t   s t o r a g e C l a s s N a m e .   F o r   t h e   P V C s   t h a t   e i t h e r   h a v e   a n   e m p t y   v a l u e   f o r   s t o r a g e C l a s s N a m e   o r   d o   n o t   h a v e   t h i s   k e y ,   t h e   c o n t r o l   p l a n e   t h e n   u p d a t e s   t h o s e   P V C s   t o   s e t   s t o r a g e C l a s s N a m e   t o   m a t c h   t h e   n e w   d e f a u l t   S t o r a g e C l a s s .   I f   y o u   h a v e   a n   e x i s t i n g   P V C   w h e r e   t h e   s t o r a g e C l a s s N a m e   i s   " " ,   a n d   y o u   c o n f i g u r e   a   d e f a u l t   S t o r a g e C l a s s ,   t h e n   t h i s   P V C   w i l l   n o t   g e t   u p d a t e d .   I n   o r d e r   t o   k e e p   b i n d i n g   t o   P V s   w i t h   s t o r a g e C l a s s N a m e   s e t   t o   " "   ( w h i l e   a   d e f a u l t   S t o r a g e C l a s s   i s   p r e s e n t ) ,   y o u   n e e d   t o   s e t   t h e   s t o r a g e C l a s s N a m e   o f   t h e   a s s o c i a t e d   P V C   t o   " " .   T h i s   b e h a v i o r   h e l p s   a d m i n i s t r a t o r s   c h a n g e   d e f a u l t   S t o r a g e C l a s s   b


Question: What is Claims As Volumes?

Answer: P o d s   a c c e s s   s t o r a g e   b y   u s i n g   t h e   c l a i m   a s   a   v o l u m e .   C l a i m s   m u s t   e x i s t   i n   t h e   s a m e   n a m e s p a c e   a s   t h e   P o d   u s i n g   t h e   c l a i m .   T h e   c l u s t e r   f i n d s   t h e   c l a i m   i n   t h e   P o d ' s   n a m e s p a c e   a n d   u s e s   i t   t o   g e t   t h e   P e r s i s t e n t V o l u m e   b a c k i n g   t h e   c l a i m .   T h e   v o l u m e   i s   t h e n   m o u n t e d   t o   t h e   h o s t   a n d   i n t o   t h e   P o d .   a p i V e r s i o n :   v 1   k i n d :   P o d   m e t a d a t a :   n a m e :   m y p o d   s p e c :   c o n t a i n e r s :   -   n a m e :   m y f r o n t e n d   i m a g e :   n g i n x   v o l u m e M o u n t s :   -   m o u n t P a t h :   " / v a r / w w w / h t m l "   n a m e :   m y p d   v o l u m e s :   -   n a m e :   m y p d   p e r s i s t e n t V o l u m e C l a i m :   c l a i m N a m e :   m y c l a i m


Question: What is A Note on Namespaces?

Answer: P e r s i s t e n t V o l u m e s   b i n d s   a r e   e x c l u s i v e ,   a n d   s i n c e   P e r s i s t e n t V o l u m e C l a i m s   a r e   n a m e s p a c e d   o b j e c t s ,   m o u n t i n g   c l a i m s   w i t h   " M a n y "   m o d e s   ( R O X ,   R W X )   i s   o n l y   p o s s i b l e   w i t h i n   o n e   n a m e s p a c e .


Question: What is PersistentVolumes typed hostPath?

Answer: A   h o s t P a t h   P e r s i s t e n t V o l u m e   u s e s   a   f i l e   o r   d i r e c t o r y   o n   t h e   N o d e   t o   e m u l a t e   n e t w o r k - a t t a c h e d   s t o r a g e .   S e e   a n   e x a m p l e   o f   h o s t P a t h   t y p e d   v o l u m e .


Question: What is Raw Block Volume Support?

Answer: T h e   f o l l o w i n g   v o l u m e   p l u g i n s   s u p p o r t   r a w   b l o c k   v o l u m e s ,   i n c l u d i n g   d y n a m i c   p r o v i s i o n i n g   w h e r e   a p p l i c a b l e :   C S I   ( i n c l u d i n g   s o m e   C S I   m i g r a t e d   v o l u m e   t y p e s ) F C   ( F i b r e   C h a n n e l ) i S C S I L o c a l   v o l u m e


Question: What is PersistentVolume using a Raw Block Volume?

Answer: a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e   m e t a d a t a :   n a m e :   b l o c k - p v   s p e c :   c a p a c i t y :   s t o r a g e :   1 0 G i   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   v o l u m e M o d e :   B l o c k   p e r s i s t e n t V o l u m e R e c l a i m P o l i c y :   R e t a i n   f c :   t a r g e t W W N s :   [ " 5 0 0 6 0 e 8 0 1 0 4 9 c f d 1 " ]   l u n :   0   r e a d O n l y :   f a l s e


Question: What is PersistentVolumeClaim requesting a Raw Block Volume?

Answer: a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   b l o c k - p v c   s p e c :   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   v o l u m e M o d e :   B l o c k   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   1 0 G i


Question: What is Pod specification adding Raw Block Device path in container?

Answer: a p i V e r s i o n :   v 1   k i n d :   P o d   m e t a d a t a :   n a m e :   p o d - w i t h - b l o c k - v o l u m e   s p e c :   c o n t a i n e r s :   -   n a m e :   f c - c o n t a i n e r   i m a g e :   f e d o r a : 2 6   c o m m a n d :   [ " / b i n / s h " ,   " - c " ]   a r g s :   [   " t a i l   - f   / d e v / n u l l "   ]   v o l u m e D e v i c e s :   -   n a m e :   d a t a   d e v i c e P a t h :   / d e v / x v d a   v o l u m e s :   -   n a m e :   d a t a   p e r s i s t e n t V o l u m e C l a i m :   c l a i m N a m e :   b l o c k - p v c


Question: What is Binding Block Volumes?

Answer: I f   a   u s e r   r e q u e s t s   a   r a w   b l o c k   v o l u m e   b y   i n d i c a t i n g   t h i s   u s i n g   t h e   v o l u m e M o d e   f i e l d   i n   t h e   P e r s i s t e n t V o l u m e C l a i m   s p e c ,   t h e   b i n d i n g   r u l e s   d i f f e r   s l i g h t l y   f r o m   p r e v i o u s   r e l e a s e s   t h a t   d i d n ' t   c o n s i d e r   t h i s   m o d e   a s   p a r t   o f   t h e   s p e c .   L i s t e d   i s   a   t a b l e   o f   p o s s i b l e   c o m b i n a t i o n s   t h e   u s e r   a n d   a d m i n   m i g h t   s p e c i f y   f o r   r e q u e s t i n g   a   r a w   b l o c k   d e v i c e .   T h e   t a b l e   i n d i c a t e s   i f   t h e   v o l u m e   w i l l   b e   b o u n d   o r   n o t   g i v e n   t h e   c o m b i n a t i o n s :   V o l u m e   b i n d i n g   m a t r i x   f o r   s t a t i c a l l y   p r o v i s i o n e d   v o l u m e s :


Question: What is Volume Snapshot and Restore Volume from Snapshot Support?

Answer: V o l u m e   s n a p s h o t s   o n l y   s u p p o r t   t h e   o u t - o f - t r e e   C S I   v o l u m e   p l u g i n s .   F o r   d e t a i l s ,   s e e   V o l u m e   S n a p s h o t s .   I n - t r e e   v o l u m e   p l u g i n s   a r e   d e p r e c a t e d .   Y o u   c a n   r e a d   a b o u t   t h e   d e p r e c a t e d   v o l u m e   p l u g i n s   i n   t h e   V o l u m e   P l u g i n   F A Q .


Question: What is Create a PersistentVolumeClaim from a Volume Snapshot?

Answer: a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   r e s t o r e - p v c   s p e c :   s t o r a g e C l a s s N a m e :   c s i - h o s t p a t h - s c   d a t a S o u r c e :   n a m e :   n e w - s n a p s h o t - t e s t   k i n d :   V o l u m e S n a p s h o t   a p i G r o u p :   s n a p s h o t . s t o r a g e . k 8 s . i o   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   1 0 G i


Question: What is Volume Cloning?

Answer: V o l u m e   C l o n i n g   o n l y   a v a i l a b l e   f o r   C S I   v o l u m e   p l u g i n s .


Question: What is Create PersistentVolumeClaim from an existing PVC?

Answer: a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   c l o n e d - p v c   s p e c :   s t o r a g e C l a s s N a m e :   m y - c s i - p l u g i n   d a t a S o u r c e :   n a m e :   e x i s t i n g - s r c - p v c - n a m e   k i n d :   P e r s i s t e n t V o l u m e C l a i m   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   1 0 G i


Question: What is Volume populators and data sources?

Answer: K u b e r n e t e s   s u p p o r t s   c u s t o m   v o l u m e   p o p u l a t o r s .   T o   u s e   c u s t o m   v o l u m e   p o p u l a t o r s ,   y o u   m u s t   e n a b l e   t h e   A n y V o l u m e D a t a S o u r c e   f e a t u r e   g a t e   f o r   t h e   k u b e - a p i s e r v e r   a n d   k u b e - c o n t r o l l e r - m a n a g e r .   V o l u m e   p o p u l a t o r s   t a k e   a d v a n t a g e   o f   a   P V C   s p e c   f i e l d   c a l l e d   d a t a S o u r c e R e f .   U n l i k e   t h e   d a t a S o u r c e   f i e l d ,   w h i c h   c a n   o n l y   c o n t a i n   e i t h e r   a   r e f e r e n c e   t o   a n o t h e r   P e r s i s t e n t V o l u m e C l a i m   o r   t o   a   V o l u m e S n a p s h o t ,   t h e   d a t a S o u r c e R e f   f i e l d   c a n   c o n t a i n   a   r e f e r e n c e   t o   a n y   o b j e c t   i n   t h e   s a m e   n a m e s p a c e ,   e x c e p t   f o r   c o r e   o b j e c t s   o t h e r   t h a n   P V C s .   F o r   c l u s t e r s   t h a t   h a v e   t h e   f e a t u r e   g a t e   e n a b l e d ,   u s e   o f   t h e   d a t a S o u r c e R e f   i s   p r e f e r r e d   o v e r   d a t a S o u r c e .


Question: What is Cross namespace data sources?

Answer: K u b e r n e t e s   s u p p o r t s   c r o s s   n a m e s p a c e   v o l u m e   d a t a   s o u r c e s .   T o   u s e   c r o s s   n a m e s p a c e   v o l u m e   d a t a   s o u r c e s ,   y o u   m u s t   e n a b l e   t h e   A n y V o l u m e D a t a S o u r c e   a n d   C r o s s N a m e s p a c e V o l u m e D a t a S o u r c e   f e a t u r e   g a t e s   f o r   t h e   k u b e - a p i s e r v e r   a n d   k u b e - c o n t r o l l e r - m a n a g e r .   A l s o ,   y o u   m u s t   e n a b l e   t h e   C r o s s N a m e s p a c e V o l u m e D a t a S o u r c e   f e a t u r e   g a t e   f o r   t h e   c s i - p r o v i s i o n e r .   E n a b l i n g   t h e   C r o s s N a m e s p a c e V o l u m e D a t a S o u r c e   f e a t u r e   g a t e   a l l o w s   y o u   t o   s p e c i f y   a   n a m e s p a c e   i n   t h e   d a t a S o u r c e R e f   f i e l d .


Question: What is Data source references?

Answer: T h e   d a t a S o u r c e R e f   f i e l d   b e h a v e s   a l m o s t   t h e   s a m e   a s   t h e   d a t a S o u r c e   f i e l d .   I f   o n e   i s   s p e c i f i e d   w h i l e   t h e   o t h e r   i s   n o t ,   t h e   A P I   s e r v e r   w i l l   g i v e   b o t h   f i e l d s   t h e   s a m e   v a l u e .   N e i t h e r   f i e l d   c a n   b e   c h a n g e d   a f t e r   c r e a t i o n ,   a n d   a t t e m p t i n g   t o   s p e c i f y   d i f f e r e n t   v a l u e s   f o r   t h e   t w o   f i e l d s   w i l l   r e s u l t   i n   a   v a l i d a t i o n   e r r o r .   T h e r e f o r e   t h e   t w o   f i e l d s   w i l l   a l w a y s   h a v e   t h e   s a m e   c o n t e n t s .   T h e r e   a r e   t w o   d i f f e r e n c e s   b e t w e e n   t h e   d a t a S o u r c e R e f   f i e l d   a n d   t h e   d a t a S o u r c e   f i e l d   t h a t   u s e r s   s h o u l d   b e   a w a r e   o f :   T h e   d a t a S o u r c e   f i e l d   i g n o r e s   i n v a l i d   v a l u e s   ( a s   i f   t h e   f i e l d   w a s   b l a n k )   w h i l e   t h e   d a t a S o u r c e R e f   f i e l d   n e v e r   i g n o r e s   v a l u e s   a n d   w i l l   c a u s e   a n   e r r o r   i f   a n   i n v a l i d   v a l u e   i s   u s e d .   I n v a l i d   v a l u e s   a r e   a n y   c o r e   o b j e c t   ( o b j e c t s   w i t h   n o   a p i G r o u p )   e x c e p t   f o r   P V C s . T h e   d a t a S o u r c e R e f   f i e l d   m a y   c o n t a i n   d i f f e r e n t   t y p e s   o f   o b j e c t s ,   w h i l e   t h e   d a t a S o u r c e   f i e l d   o n l y   a l l o w s   P V C s   a n d   V o l u m e S n a p s h o t s .   W h e n   t h e   C r o s s N a m e s p a c e V o l u m e D a t a S o u r c e   f e a t u r e   i s   e n a b l e d ,   t h e r e   a r e   a d d i t i o n a l   d i f f e r e n c e s :   T h e   d a t a S o u r c e   f i e l d   o n l y   a l l o w s   l o c


Question: What is Using volume populators?

Answer: V o l u m e   p o p u l a t o r s   a r e   c o n t r o l l e r s   t h a t   c a n   c r e a t e   n o n - e m p t y   v o l u m e s ,   w h e r e   t h e   c o n t e n t s   o f   t h e   v o l u m e   a r e   d e t e r m i n e d   b y   a   C u s t o m   R e s o u r c e .   U s e r s   c r e a t e   a   p o p u l a t e d   v o l u m e   b y   r e f e r r i n g   t o   a   C u s t o m   R e s o u r c e   u s i n g   t h e   d a t a S o u r c e R e f   f i e l d :   a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   p o p u l a t e d - p v c   s p e c :   d a t a S o u r c e R e f :   n a m e :   e x a m p l e - n a m e   k i n d :   E x a m p l e D a t a S o u r c e   a p i G r o u p :   e x a m p l e . s t o r a g e . k 8 s . i o   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   1 0 G i   B e c a u s e   v o l u m e   p o p u l a t o r s   a r e   e x t e r n a l   c o m p o n e n t s ,   a t t e m p t s   t o   c r e a t e   a   P V C   t h a t   u s e s   o n e   c a n   f a i l   i f   n o t   a l l   t h e   c o r r e c t   c o m p o n e n t s   a r e   i n s t a l l e d .   E x t e r n a l   c o n t r o l l e r s   s h o u l d   g e n e r a t e   e v e n t s   o n   t h e   P V C   t o   p r o v i d e


Question: What is Using a cross-namespace volume data source?

Answer: C r e a t e   a   R e f e r e n c e G r a n t   t o   a l l o w   t h e   n a m e s p a c e   o w n e r   t o   a c c e p t   t h e   r e f e r e n c e .   Y o u   d e f i n e   a   p o p u l a t e d   v o l u m e   b y   s p e c i f y i n g   a   c r o s s   n a m e s p a c e   v o l u m e   d a t a   s o u r c e   u s i n g   t h e   d a t a S o u r c e R e f   f i e l d .   Y o u   m u s t   a l r e a d y   h a v e   a   v a l i d   R e f e r e n c e G r a n t   i n   t h e   s o u r c e   n a m e s p a c e :   a p i V e r s i o n :   g a t e w a y . n e t w o r k i n g . k 8 s . i o / v 1 b e t a 1   k i n d :   R e f e r e n c e G r a n t   m e t a d a t a :   n a m e :   a l l o w - n s 1 - p v c   n a m e s p a c e :   d e f a u l t   s p e c :   f r o m :   -   g r o u p :   " "   k i n d :   P e r s i s t e n t V o l u m e C l a i m   n a m e s p a c e :   n s 1   t o :   -   g r o u p :   s n a p s h o t . s t o r a g e . k 8 s . i o   k i n d :   V o l u m e S n a p s h o t   n a m e :   n e w - s n a p s h o t - d e m o   a p i V e r s i o n :   v 1   k i n d :   P e r s i s t e n t V o l u m e C l a i m   m e t a d a t a :   n a m e :   f o o - p v c   n a m e s p a c e :   n s 1   s p e c :   s t o r a g e C l a s s N a m e :   e x a m p l e   a c c e s s M o d e s :   -   R e a d W r i t e O n c e   r e s o u r c e s :   r e q u e s t s :   s t o r a g e :   1 G i   d a t a S o u r c e R e f :   a p i G r o u p :   s n a p s h o t . s t o r a g e . k 8 s . i o   k i n d :   V o l u m e S n a p s h o t   n a m e :   n e w - s n a p s h o t - d e m o   n a m e s p a c e :   d e f a u l t   v o l u m e M o d e :   F i l e s y s t e m


Question: What is Writing Portable Configuration?

Answer: I f   y o u ' r e   w r i t i n g   c o n f i g u r a t i o n   t e m p l a t e s   o r   e x a m p l e s   t h a t   r u n   o n   a   w i d e   r a n g e   o f   c l u s t e r s   a n d   n e e d   p e r s i s t e n t   s t o r a g e ,   i t   i s   r e c o m m e n d e d   t h a t   y o u   u s e   t h e   f o l l o w i n g   p a t t e r n :   I n c l u d e   P e r s i s t e n t V o l u m e C l a i m   o b j e c t s   i n   y o u r   b u n d l e   o f   c o n f i g   ( a l o n g s i d e   D e p l o y m e n t s ,   C o n f i g M a p s ,   e t c ) . D o   n o t   i n c l u d e   P e r s i s t e n t V o l u m e   o b j e c t s   i n   t h e   c o n f i g ,   s i n c e   t h e   u s e r   i n s t a n t i a t i n g   t h e   c o n f i g   m a y   n o t   h a v e   p e r m i s s i o n   t o   c r e a t e   P e r s i s t e n t V o l u m e s . G i v e   t h e   u s e r   t h e   o p t i o n   o f   p r o v i d i n g   a   s t o r a g e   c l a s s   n a m e   w h e n   i n s t a n t i a t i n g   t h e   t e m p l a t e . I f   t h e   u s e r   p r o v i d e s   a   s t o r a g e   c l a s s   n a m e ,   p u t   t h a t   v a l u e   i n t o   t h e   p e r s i s t e n t V o l u m e C l a i m . s t o r a g e C l a s s N a m e   f i e l d .   T h i s   w i l l   c a u s e   t h e   P V C   t o   m a t c h   t h e   r i g h t   s t o r a g e   c l a s s   i f   t h e   c l u s t e r   h a s   S t o r a g e C l a s s e s   e n a b l e d   b y   t h e   a d m i n . I f   t h e   u s e r   d o e s   n o t   p r o v i d e   a   s t o r a g e   c l a s s   n a m e ,   l e a v e   t h e   p e r s i s t e n t V o l u m e C l a i m . s t o r a g e C l a s s N a m e   f i e l d   a s   n i l .   T h i s   w i l l   c a u s e   a   P V   t o   b e   a u t o m a t i c a l l y   p r o v i s i o n e d   f o r   t h e   u s e r   w i t h   t h e   d e f a u l t   S t o r a g e C l a s s   i n   t h e   c l u s t e r .   M a n y   c l u s t e r   e n v i r o n m e n t s   h a v e   a


Question: What is What's next?

Answer: L e a r n   m o r e   a b o u t   C r e a t i n g   a   P e r s i s t e n t V o l u m e . L e a r n   m o r e   a b o u t   C r e a t i n g   a   P e r s i s t e n t V o l u m e C l a i m . R e a d   t h e   P e r s i s t e n t   S t o r a g e   d e s i g n   d o c u m e n t .


Question: What is API references?

Answer: R e a d   a b o u t   t h e   A P I s   d e s c r i b e d   i n   t h i s   p a g e :   P e r s i s t e n t V o l u m e P e r s i s t e n t V o l u m e C l a i m


Question: What is Image Policy API (v1alpha1)?

Answer: Image Policy API (v1alpha1)Resource TypesImageReviewImageReviewImageReview checks if the set of images in a pod are allowed.FieldDescriptionapiVersionstringimagepolicy.k8s.io/v1alpha1kindstringImageReviewmetadatameta/v1.ObjectMetaStandard object's metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadataRefer to the Kubernetes API documentation for the fields of the metadata field.spec [Required]ImageReviewSpecSpec holds information about the pod being evaluatedstatusImageReviewStatusStatus is filled in by the backend and indicates whether the pod should be allowed.ImageReviewContainerSpecAppears in:ImageReviewSpecImageReviewContainerSpec is a description of a container within the pod creation request.FieldDescriptionimagestringThis can be in the form image:tag or image@SHA:012345679abcdef.ImageReviewSpecAppears in:ImageReviewImageReviewSpec is a description of the pod creation request.FieldDescriptioncontainers[]ImageReviewContainerSpecContainers is a list of a subset of the information in each container of the Pod being created.annotationsmap[string]stringAnnotations is a list of key-value pairs extracted from the Pod's annotations. It only includes keys which match the pattern *.image-policy.k8s.io/*. It is up to each webhook backend to determine how to interpret these annotations, if at all.namespacestringNamespace is the namespace the pod is being created in.ImageReviewStatusAppears in:ImageReviewImageReviewStatus is the result of the review for the pod creation request.FieldDescriptionallowed [Required]boolAllowed indicates that all images were allowed to be run.reasonstringReason should be empty unless Allowed is false in which case it may contain a short description of what is wrong. Kubernetes may truncate excessively long errors when displaying to the user.auditAnnotationsmap[string]stringAuditAnnotations will be added to the attributes object of the admission controller request using 'AddAnnotation'. The keys should be prefix-less (i.e., the admission controller will add an appropriate prefix).This page is automatically generated.If you plan to report an issue with this page, mention that the page is auto-generated in your issue description. The fix may need to happen elsewhere in the Kubernetes project.