Persistent volumes and storage classes

Persistent volumes (PVs) and Persistent volume claims (PVCs) define the persistent storage. Dynamic storage classes are used to automatically provision PVs for the applications that are deployed. The storage classes and persistent volumes describe the type of storage that is used by the applications in the cluster.

Use of file-based storage requires ReadWriteMany (RWX) permissions. File-based storage is supported through platform storage Container Storage Interface (CSI) drivers, like the NetApp Trident ONTAP NAS driver or the Azure Files CSI for the Network File System (NFS) driver. For each of the folders on a file-based system like NFS, all anonymous connections must be configured to values without permissions.

On NFS, use the default NFS anongid value. If the no_root_squash option is used, the owner GID value is 0. The NFS export root_squash option is recommended for security. If you use the root_squash option, then the file directories to be used for the PVs group ownership must be set to the anongid in the NFS export definition. The default anongid value is 65534.

Consider the following possibilities when you apply permissions to your folders:

  • If the no_root_squash option is used, the PV group ownership must be set to the root group 0.
  • Assign read, write, execute permissions to both the user and group owners, for example, chmod 770.
  • Content Cortex requires the following NFS exports:
    • The rw, sync, no_wdelay settings are required.
    • The no_subtree_check setting is recommended for performance.