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Documentation Index

Fetch the complete documentation index at: https://docs.ankra.io/llms.txt

Use this file to discover all available pages before exploring further.

The Storage section provides visibility into persistent storage resources in your Kubernetes cluster.

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Overview

Kubernetes storage resources manage persistent data:
  • PersistentVolumes (PV) - Cluster-wide storage resources
  • PersistentVolumeClaims (PVC) - Requests for storage by pods
  • StorageClasses - Define storage provisioners and policies
  • CSI Drivers - Container Storage Interface implementations
  • CSI Nodes - Node-level CSI capabilities
  • Volume Attachments - Track volume attachments to nodes

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Accessing Storage Resources

Navigate to your cluster and click Kubernetes in the sidebar. Storage resources include:
ResourcePath
PersistentVolumesKubernetes → PersistentVolumes
PersistentVolumeClaimsKubernetes → PersistentVolumeClaims
StorageClassesKubernetes → StorageClasses
CSI DriversKubernetes → CSI Drivers
CSI NodesKubernetes → CSI Nodes

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PersistentVolumes (PV)

PersistentVolumes are cluster-level storage resources.

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Viewing PersistentVolumes

ColumnDescription
NameVolume name
CapacityStorage size
Access ModesRWO, ROX, RWX
Reclaim PolicyRetain, Delete, Recycle
StatusAvailable, Bound, Released, Failed
ClaimBound PVC (if any)
StorageClassAssociated storage class
AgeTime since creation

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Access Modes

ModeDescription
RWOReadWriteOnce - single node read-write
ROXReadOnlyMany - multiple nodes read-only
RWXReadWriteMany - multiple nodes read-write

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Reclaim Policies

PolicyDescription
RetainKeep data after PVC deletion
DeleteDelete underlying storage
RecycleBasic scrub (rm -rf /data/*)

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PV Details

Click a PV to view:
  • Capacity - Storage size
  • Volume Mode - Filesystem or Block
  • Access Modes - Supported access patterns
  • Reclaim Policy - What happens when released
  • Storage Class - Provisioner configuration
  • Claim Reference - Bound PVC details
  • Source - Underlying storage (CSI, NFS, etc.)

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PersistentVolumeClaims (PVC)

PVCs are requests for storage by pods.

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Viewing PersistentVolumeClaims

ColumnDescription
NameClaim name
NamespaceKubernetes namespace
StatusPending, Bound, Lost
VolumeBound PV name
CapacityRequested/actual storage
Access ModesRequested access modes
StorageClassStorage class used
AgeTime since creation

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PVC States

StatusDescription
PendingWaiting for a matching PV
BoundSuccessfully bound to a PV
LostPV was deleted or unavailable

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PVC Details

Click a PVC to view:
  • Request - Requested storage size
  • Capacity - Actual provisioned size
  • Access Modes - Granted access modes
  • Volume Name - Bound PersistentVolume
  • Storage Class - Provisioner used
  • Volume Mode - Filesystem or Block
  • Pods - Pods using this claim

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Troubleshooting Pending PVCs

  1. Check if a matching StorageClass exists
  2. Verify storage class is set to provision dynamically
  3. Check cloud provider quotas and limits
  4. Review PVC events for errors

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StorageClasses

StorageClasses define how storage is provisioned.

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Viewing StorageClasses

ColumnDescription
NameClass name
ProvisionerCSI driver or provisioner
Reclaim PolicyDefault reclaim policy
Volume Binding ModeImmediate or WaitForFirstConsumer
DefaultWhether this is the default class

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Volume Binding Modes

ModeDescription
ImmediateProvision volume immediately
WaitForFirstConsumerWait until pod is scheduled

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StorageClass Details

  • Provisioner - CSI driver name
  • Parameters - Provisioner-specific settings
  • Reclaim Policy - Default for created PVs
  • Allow Volume Expansion - Whether resize is supported
  • Mount Options - Default mount options

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Common Provisioners

ProvisionerProvider
kubernetes.io/aws-ebsAWS EBS
kubernetes.io/gce-pdGoogle Persistent Disk
kubernetes.io/azure-diskAzure Disk
ebs.csi.aws.comAWS EBS CSI
pd.csi.storage.gke.ioGKE CSI

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CSI Resources

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CSI Drivers

CSI Drivers are storage plugins that implement the Container Storage Interface.
ColumnDescription
NameDriver name
Attach RequiredWhether attach operation is needed
Pod Info On MountWhether pod info is passed on mount

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CSI Nodes

CSI Nodes show storage capabilities per node.
ColumnDescription
NameNode name
DriversInstalled CSI drivers
AllocatableMaximum volumes per driver

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Common Tasks

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Finding Which Pod Uses a PVC

  1. Navigate to PersistentVolumeClaims
  2. Click on the PVC
  3. View the Pods section to see which pods have mounted this volume

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Expanding a Volume

  1. Navigate to PersistentVolumeClaims
  2. Click on the PVC
  3. Check if the StorageClass allows expansion
  4. Edit the PVC to request more storage
  5. The filesystem will be expanded (may require pod restart)

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Troubleshooting Storage Issues

  1. PVC Pending:
    • Check StorageClass exists and is valid
    • Verify provisioner is running
    • Check cloud provider quotas
    • Review events for error messages
  2. Mount Failures:
    • Check node can access the storage
    • Verify CSI driver is installed on the node
    • Check for conflicting access modes
  3. Data Loss:
    • Check reclaim policy before deleting PVCs
    • Use Retain policy for important data
    • Set up backup solutions

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Tips

WaitForFirstConsumer: Use this binding mode to ensure volumes are provisioned in the same zone as your pod.
Storage Class Defaults: Set a default StorageClass so PVCs without explicit class still work.
Reclaim Policy: Change to Retain for production data to prevent accidental deletion.
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