[Gluster-users] Removing subvolume from dist/rep volume

[Dave Sherohman]

I have a 9-brick, replica 2+A cluster and plan to (permanently) remove
one of the three subvolumes.  I think I've worked out how to do it, but
want to verify first that I've got it right, since downtime or data loss
would be Bad Things.

The current configuration has six data bricks across six hosts (B
through G), and all three arbiter bricks on the same host (A), such as
one might create with

# gluster volume create myvol replica 3 arbiter 1 B:/data C:/data A:/arb1 D:/data E:/data A:/arb2 F:/data G:/data A:/arb3


My objective is to remove nodes B and C entirely.

First up is to pull their bricks from the volume:

# gluster volume remove-brick myvol B:/data C:/data A:/arb1 start
(wait for data to be migrated)
# gluster volume remove-brick myvol B:/data C:/data A:/arb1 commit

And then remove the nodes with:

# gluster peer detach B
# gluster peer detach C


Is this correct, or did I forget any steps and/or mangle the syntax on
any commands?

Also, for the remove-brick command, is there any way to throttle the
amount of bandwidth which will be used for the data migration?
Unfortunately, I was not able to provision a dedicated VLAN for the
gluster servers to communicate among themselves, so I don't want it
hogging all available capacity if that can be avoided.


If it makes a difference, my gluster version is 3.12.15-1, running on
Debian and installed from the debs at

deb https://download.gluster.org/pub/gluster/glusterfs/3.12/LATEST/Debian/9/amd64/apt stretch main

-- 
Dave Sherohman