The RBD CSI plugin will provision new RBD images and attach and mount those to workloads. Currently, the default mounter is krbd, which uses the kernel rbd driver to mount the rbd images onto the application node. Here on at ceph-csi we will also have a userspace way of mounting the RBD images, via RBD-NBD.
Rbd-nbd is a client for RADOS block device (rbd) images like the existing rbd kernel module. It will map an rbd image to an NBD (Network Block Device) device, allowing access to it as a regular local block device.
It’s worth to make a note that the rbd-nbd processes will run on the
client-side, which is inside the csi-rbdplugin node plugin.
To use the rbd-nbd mounter for RBD-backed PVs, set mounter to rbd-nbd
in the StorageClass.
Rbd-nbd support status: Alpha
| Features | Feature Status | CSI Driver Version | Ceph Cluster Version | CSI Spec Version | Kubernetes Version |
|---|---|---|---|---|---|
| Creating and deleting snapshot | Alpha | >= v3.4.0 | Pacific (>=16.0.0) | >= v1.0.0 | >= v1.17.0 |
| Creating and deleting clones | Alpha | >= v3.4.0 | Pacific (>=16.0.0) | >= v1.0.0 | >= v1.17.0 |
NOTE: The Alpha status reflects possible non-backward compatible
changes in the future, and is thus not recommended for production use.
Please refer to the matrix in the Kubernetes documentation.