On 2019-08-20 17:05, Yousif Alkhateeb via dovecot wrote:
Hello ,
I have an active passive dovecot setup with glusterfs as a mail
storage and using maildirs, we used to have a problem when users with
large mailboxes sync their folders. This caused the load average to
increase in the server , after a while we have enabled the
very_dirty_sync option in dovecot , things got better and the problem
disappeared but we need to know if there is any thing else that we
need to do or know about the very_dirty_sync option that may cause
future problems .
Last time I tested Glusterfs as mail storage (stock RHEL 6 kernel, think
6-7 years ago?) the performance on large maildirs was abysmal. We've
ended up with DRBD & NFS (TCP, with UDP it'd freeze in less than half an
hour under stress testing) and haven't looked back since. I know this
isn't the answer you're looking for and I don't know how your deployment
looks like, nor the scale, but I'm just chipping in. Tuning various
Dovecot may be just kicking the can down the road, looking into
alternate storage backends could be an option you should perhaps
consider.
Cheers,
--
Adi Pircalabu
