Re: [squid-users] WARNING - Queue congestion

ons 2006-03-29 klockan 18:13 -0300 skrev Rodrigo A B Freire:

> From time to time, a disk started a write operation (monitored via iostat)
> which lasted some times up to 20 seconds. When these ' disk flush' happened,
> the system just stall; waiting for this disk queue emptying, blocking every
> disk I/O. Meanwhile, the *squid operations* got queued, generating the
> warning.

From what I have understood of ext3 the above happens if the journal
gets full.. Having the fs mounted with noatime helps somewhat in
reducing this as there is much less metadata updates.

It is possible that the journal mode data=writeback could help this as
well, especially if combined with suitable elevator tunings..

Also commit=1 would probably help in making the system run smoother
under load. And should also reduce the demand on the journal size..

Regards
Henrik