Raw block volume support

Last published : Jul 06, 2026
Using raw block volume, the block device is directly exposed instead of exposing the mountpoint inside an application container. Applications can directly write or can create their own native filesystem on the provided block device.
Raw block volumes support is required for applications that are capable of accessing the device directly to store data. Database application is an example where data is directly accessed from the underlying storage, which is more efficient. To enable raw block volume support, volumeMode must be set to Block.
Following are the FileSystem-persistent volumes features which are supported on Block volumes.
  • Create and Delete Volumes
  • Expand Volumes
  • Clone Volumes
  • Create and Delete Snapshot
  • Snapshot Restore
    Note: Access mode RWO (ReadWriteOnce) is not supported for block volumes. Creation of a RWO block volume does not fail. The volume is created with RWX (ReadWriteMany) properties even when it is listed as RWO. For ROX (ReadOnlyMany) block volumes, the read-only condition is enforced on non-root users only.
For Block volumes, the CSI driver does not format the block device; it just binds the block device to the target path.