Hi,
On 10/09/23 14:28, Garrett Wollman wrote:
<<On Fri, 1 Sep 2023 01:04:56 +0200, Mateusz Guzik <[email protected]> said:
zfs lock arrays are a known problem, bumping them is definitely an option.
This is the thing I tried next. It took a few attempts (mostly I
think due to my errors) but I'm now running with 512 (instead of 64)
and plan to deploy 1024 soon, as the results are significant: while we
still see significant loads and kmem pressure during the backup
window, backups are able to complete some 5 to 8 hours sooner, and
nfsd remains responsive.
How did you bump up the zfs lock array value? Is this a sysctl-tweakable
value?
I'm currently running a recent version of stable/13 on a 24-CPU machine.
It runs Postgresql 15. If I slam the system with a "pg_restore -j 20
...", the system will freeze more often than not. This issue does not
seem to appear if I use UFS as my backing store, so I'm left to assume
that it's ZFS related. I'm wondering whether your tweaks will affect my
system's behaviour.
Cheers.
--
Jonathan Chen <[email protected]>
