On Fri, May 04, 2018 at 10:11:39AM +0530, Durga Prasad Malyala wrote:
> I am seeing consistent delays in writing to disk (my System redhat 7.2
> using GFS2 file system cluster)
I think 7.5 is current. Don't you want to upgrade?
The Red Hat support you pay for covers GFS2, Postfix and Dovecot. What
did they tell you?
> May 4 10:03:34 mail1 postfix/lmtp[11662]: E4EB75048C19:
> to=<x...@xyz.com>, relay=mail.xyz.com[private/dovecot-lmtp], delay=50,
> delays=0.02/0/0/50, dsn=2.0.0, status=sent (250 2.0.0 <x...@xyz.com>
> IIt4Ejji61o3LgAAuUaIWw Saved)
>
> during major bursts of receiving mailq delays goes upto 600+ also.
I don't think Dovecot is part of Postfix. Do you?
> GFS2 writing is OK. Not as great as XFS but OK. Disk bottleneck is
> ruled out as it is a 3PAR SAN with 16 Gbps FC.
How did you check that writing is OK? What did your load tests show as
maximum possible mail throughput? Mail needs a lot of fsync, which in
fact is sensitive to latency.
> ocassionally we get "timed out while sending end of data -- message
> may be sent more than once)" message also and Message goes to deferred
> queue.
Well, check your Dovecot log. Postfix is just the messenger.
Bastian
--
Vulcans never bluff.
-- Spock, "The Doomsday Machine", stardate 4202.1
