Enabling and disabling image features

The Ceph Block Device image features, such as fast-diff, exclusive-lock, object-map, or deep-flatten, are enabled by default. You can enable or disable these image features on already existing images.

Note: The deep flatten feature can be only disabled on already existing images but not enabled. To use deep flatten, enable it when creating images.

Prerequisites

A running IBM Storage Ceph cluster.
Root-level access to the client node.

Procedure

Retrieve information from a particular image in a pool:

Syntax

rbd --image POOL_NAME/IMAGE_NAME info

Example

[ceph: root@host01 /]# rbd --image pool1/image1 info

Enable a feature:

Syntax
```
rbd feature enable POOL_NAME/IMAGE_NAME FEATURE_NAME
```
- To enable the exclusive-lock feature on the image1 image in the pool1 pool:
  Example
```
    [ceph: root@host01 /]# rbd feature enable pool1/image1 exclusive-lock
```
  Important: If you enable the fast-diff and object-map features, then rebuild the object map:
  rbd object-map rebuild POOL_NAME/IMAGE_NAME

Disable a feature:

Syntax

rbd feature disable POOL_NAME/IMAGE_NAME FEATURE_NAME

To disable the fast-diff feature on the image1 image in the pool1 pool:

Example

    [ceph: root@host01 /]# rbd feature disable pool1/image1 fast-diff