Advanced configuration - Rook

All CephNFS daemons are configured using shared RADOS objects stored in a Ceph pool named .nfs. Users can modify the configuration object for each CephNFS cluster if they wish to customize the configuration.

Changing configuration of the .nfs pool

By default, Rook creates the .nfs pool with Ceph's default configuration. If you wish to change the configuration of this pool (for example to change its failure domain or replication factor), you can create a CephBlockPool with the spec.name field set to .nfs. This pool must be replicated and cannot be erasure coded. deploy/examples/nfs.yaml contains a sample for reference.

Adding custom NFS-Ganesha config file changes

Ceph uses NFS-Ganesha servers. The config file format for these objects is documented in the NFS-Ganesha project.

Use Ceph's rados tool from the toolbox to interact with the configuration object. The below command will get you started by dumping the contents of the config object to stdout. The output will look something like the example shown if you have already created two exports as documented above. It is best not to modify any of the export objects created by Ceph so as not to cause errors with Ceph's export management.

console

$ rados --pool <pool> --namespace <namespace> get conf-nfs.<cephnfs-name> -
%url "rados://<pool>/<namespace>/export-1"
%url "rados://<pool>/<namespace>/export-2"

rados ls and rados put are other commands you will want to work with the other shared configuration objects.

Of note, it is possible to pre-populate the NFS configuration and export objects prior to creating CephNFS server clusters.

Creating NFS export over RGW

!!! warning RGW NFS export is experimental for the moment. It is not recommended for scenario of modifying existing content.

For creating an NFS export over RGW(CephObjectStore) storage backend, the below command can be used. This creates an export for the /testrgw pseudo path on an existing bucket bkt4exp as an example. You could use /testrgw pseudo for nfs mount operation afterwards.

console

ceph nfs export create rgw my-nfs /testrgw bkt4exp

Deploying a different NFS Ganesha version

The default behavior is to use CephCluster.spec.cephVersion.image as the basis for the NFS Ganesha pods. This may be overridden in order to change the NFS Ganesha version independently of the version bundled in the image used for the other Ceph cluster components. A example of why this might be desirable is to allow the use of unmodified official Ceph OCI images for all other Ceph cluster components, while still allowing the version of NFS Ganesha to be upgraded independently.

The image must contain the NFS Ganesha and dbus packages. If the SSSD sidecar is enabled, the image must also contain the sssd-client package.

yaml

apiVersion: ceph.rook.io/v1
kind: CephNFS
metadata:
  name: my-nfs
  namespace: rook-ceph
spec:
  rados:
    pool: my-nfs-data0
  server:
    active: 1
    image: custom/ganesha-image:latest"
    imagePullPolicy: Always