[Gluster-users] Perfomance issue on a 90+% full file system

[Dan Mons]

On 7 October 2014 08:56, Jeff Darcy <jdarcy at redhat.com> wrote:
> I can't think of a good reason for such a steep drop-off in GlusterFS.
> Sure, performance should degrade somewhat due to fragmenting, but not
> suddenly.  It's not like Lustre, which would do massive preallocation
> and fall apart when there was no longer enough space to do that.  It
> might be worth measuring average latency at the local-FS level, to see
> if the problem is above or below that line.

Happens like clockwork for us.  The moment we get alerts saying the
file system has hit 90%, we get a flood of support tickets about
performance.

It happens to a lesser degree on standard CentOS NAS units running XFS
we have around the place.  But again, I see the same sort of thing on
any file system (vendor supplied, self-built, OS and FS agnostic).
And yes, it's measurable (Munin graphs show it off nicely).

-Dan