8.3. Expanding Volumes
Volumes can be expanded while the trusted storage pool is online and available. For example, you can add a brick to a distributed volume, which increases distribution and adds capacity to the Red Hat Storage volume. Similarly, you can add a group of bricks to a distributed replicated volume, which increases the capacity of the Red Hat Storage volume.
Note
When expanding distributed replicated or distributed striped volumes, the number of bricks being added must be a multiple of the replica or stripe count. For example, to expand a distributed replicated volume with a replica count of 2, you need to add bricks in multiples of 2 (such as 4, 6, 8, etc.).
Expanding a Volume
- From any server in the trusted storage pool, use the following command to probe the server on which you want to add a new brick :
# gluster peer probe HOSTNAMEFor example:# gluster peer probe server4 Probe successful
- Add the brick using the following command:
# gluster volume add-brick VOLNAME NEW_BRICKFor example:# gluster volume add-brick test-volume server4:/exp4 Add Brick successful
If you want to change the replica/stripe count, you must add the replica/stripe count to theadd-brickcommand.For example,# gluster volume add-brick replica 2 test-volume server4:/exp4
When increasing the replica/stripe count of a distribute replicate/stripe volume, the number of replica/stripe bricks to be added must be equal to the number of distribute subvolumes. - Check the volume information using the following command:
# gluster volume infoThe command output displays information similar to the following:Volume Name: test-volume Type: Distribute-Replicate Status: Started Number of Bricks: 4 Bricks: Brick1: server1:/exp1 Brick2: server2:/exp2 Brick3: server3:/exp3 Brick4: server4:/exp4
- Rebalance the volume to ensure that files are distributed to the new brick. Use the rebalance command as described in Section 8.7, “Rebalancing Volumes”.
Important
The
add-brick command should be followed by a rebalance operation to ensure better utilization of the added bricks.
