[Gluster-users] Proper procedure to reduce an active volume

[Nag Pavan Chilakam]

On Fri, 5 Feb 2021, 12:27 Diego Zuccato, <diego.zuccato at unibo.it> wrote:

> Il 04/02/21 19:28, Nag Pavan Chilakam ha scritto:
>
> >     What is the proper procedure to reduce a "replica 3 arbiter 1"
> volume?
> > Can you kindly elaborate the volume configuration.  Is this a plain
> > arbiter volume or is it a distributed arbiter volume?
> > Please share the volume info so that we can help you better
> Sure. Here it is. Shortened a bit :)
> -8<--
> # gluster v info
>
> Volume Name: BigVol
> Type: Distributed-Replicate
> Volume ID: c51926bd-6715-46b2-8bb3-8c915ec47e28
> Status: Started
> Snapshot Count: 0
> Number of Bricks: 28 x (2 + 1) = 84
> Transport-type: tcp
> Bricks:
> Brick1: str957-biostor2:/srv/bricks/00/BigVol
> Brick2: str957-biostor:/srv/bricks/00/BigVol
> Brick3: str957-biostq:/srv/arbiters/00/BigVol (arbiter)
> Brick4: str957-biostor2:/srv/bricks/01/BigVol
> Brick5: str957-biostor:/srv/bricks/01/BigVol
> Brick6: str957-biostq:/srv/arbiters/01/BigVol (arbiter)
> [...]
> Brick79: str957-biostor:/srv/bricks/26/BigVol
> Brick80: str957-biostor2:/srv/bricks/26/BigVol
> Brick81: str957-biostq:/srv/arbiters/26/BigVol (arbiter)
> Brick82: str957-biostor:/srv/bricks/27/BigVol
> Brick83: str957-biostor2:/srv/bricks/27/BigVol
> Brick84: str957-biostq:/srv/arbiters/27/BigVol (arbiter)
> Options Reconfigured:
> features.scrub-throttle: aggressive
> server.manage-gids: on
> features.quota-deem-statfs: on
> features.inode-quota: on
> features.quota: on
> cluster.self-heal-daemon: enable
> ssl.certificate-depth: 1
> auth.ssl-allow: str957-bio*
> features.scrub-freq: biweekly
> features.scrub: Active
> features.bitrot: on
> transport.address-family: inet
> performance.readdir-ahead: on
> nfs.disable: on
> client.ssl: on
> server.ssl: on
> server.event-threads: 8
> client.event-threads: 8
> cluster.granular-entry-heal: enable
> -8<--
>
Ok, in this case it is a 28 x volume, you will have to remove each replica
set (one dat subvolume) at one go. Eg
Gluster v remove volname  b1 b2 b3 start

>     The procedure I've found is:
> >     1) # gluster volume remove-brick VOLNAME BRICK start
> >     (repeat for each brick to be removed, but being a r3a1 should I
> remove
> >     both bricks and the arbiter in a single command or multiple ones?)
>
Yes in one single command, you need to mention the whole replica set. In
your case b1,b2,b3  b4,b5,b6 so on .
You can either mention multiple replica sets together or 1 set at a time

> > No , you can mention bricks of a distributed subvolume in one command.
> > If you are having a 1x(2+1a) volume , then you should mention only one
> > brick. Start by removing the arbiter brick
> Ok.
>
> >     2) # gluster volume remove-brick VOLNAME BRICK status
> >     (to monitor migration)
> >     3) # gluster volume remove-brick VOLNAME BRICK commit
> >     (to finalize the removal)
> >     4) umount and reformat the freed (now unused) bricks
> >     Is this safe?
> > What is the actual need to remove bricks?
> I need to move a couple of disks to a new server, to keep it all well
> balanced and increase the available space.
>
> > If you feel this volume is not needed anymore , then just delete the
> > volume, instead of going through each brick deletion
> Nono, the volume is needed and is currently hosting data I cannot
> lose... But I haven't space to copy it elsewhere...
>
> --
> Diego Zuccato
> DIFA - Dip. di Fisica e Astronomia
> Servizi Informatici
> Alma Mater Studiorum - Università di Bologna
> V.le Berti-Pichat 6/2 - 40127 Bologna - Italy
> tel.: +39 051 20 95786
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20210205/130b026f/attachment.html>