[Gluster-users] New user, couple of questions (sharding+discard, arbiters, shutting down nodes)

[Lindsay Mathieson]

I've had zero issues using client quorum (cluster.quorum-type
=auto) and three nodes/bricks. Testing using node shutdown and node kills.

I'd really recommend going with three nodes - maybe one as a arbiter volume
if disk space is an issue.

On 29 October 2015 at 03:52, Alan Hodgson <ahodgson at simkin.ca> wrote:

> I have a couple of 2-node clusters I'm hoping to move from drbd+ocfs2 to
> glusterfs. I've been testing with 3.7.4 and I have a few questions.
>
> 1) I gather that 2-node replicas have quorum issues, and if you disable
> quorum, then they have split-brain issues. Do split-brains happen even if
> the
> network link is very reliable - I have point-to-point 10Gbit, and the only
> clients will be the brick servers? If so would it make more sense to make
> this
> a 4-node cluster and use arbiter volumes?
>
> 2) Sharding looks pretty good, as the volumes will be used exclusively for
> large VM backing images. I've been testing with 1GB shard sizes and
> performance seems good. It seems that sharded volumes don't support
> discard,
> though (ie. fstrim within VM guests). Is there a timeline on when that
> might
> be implemented?. Discard seems to work right on non-sharded volumes, but
> then
> heal times seem like they'll be an issue.
>
> 3) Is there operational documentation for maintenance procedures, like how
> to
> properly shut down nodes in a way that won't impact clients?  What I got
> from
> a recent mailing list post suggests something like:
>
> killall glusterfs
> killall glusterfsd
> systemctl stop glusterd
>
> That seems to work in testing, the client VM's stay responsive. Is it safe?
>
> Thanks in advance for any advice.
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://www.gluster.org/mailman/listinfo/gluster-users
>



-- 
Lindsay
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20151029/63f3c4a7/attachment.html>