GlusterFS - Why is it not recommended to use the root partition?

Question

I am planning to set up a number of nodes to create a distributed-replicated volume using glusterfs

I created a gluster replicated volume on two nodes using a directory on the primary (and only) partition.

gluster volume create vol_dist-replica replica 2 transport tcp 10.99.0.3:/glusterfs/dist-replica 10.99.0.4:/glusterfs/dist-replica

This returned the following warning

volume create: vol_dist-replica: failed: The brick 10.99.0.3:/glusterfs/dist-replica is being created in the root partition. It is recommended that you don't use the system's root partition for storage backend. Or use 'force' at the end of the command if you want to override this behavior.

So I used force on the end and the volume was created. I was then able to mount the gluster volume to a local directory.

My question is, why is it not recommended to use the root partition?

I can only think of the obvious reason that the system may never boot for xyz reason and therefore you'd lose the brick contents of one node.. But surely if you have enough nodes you should be able to recover from that?

Myrlmyrle

The other reason I can see is that the root filesystem will run out of space if the gluster volume does. – Myrlmyrle

Answer 1

here is an example of why not to do it:

volume remove-brick commit force: failed: Volume X does not exist

No volumes present in cluster

volume create: X: failed: /export/gv01/brick or a prefix of it is already part of a volume

perfect loop I cannot escape.

Junji