[Dovecot] POP3 Dovecot Auth CPU usage 75%+

[Timo Sirainen]

On 12.4.2012, at 23.46, Root Kev wrote:

> I hope someone can help me, I have been testing out Dovecot to switch from
> popa3d which I use at the moment.  When I get several users connecting and
> disconnection multiple times, the Dovecot process with command Auth uses
> 50-90% of the CPU for the period which they are connecting.  I am wondering
> if there is something that I may have misconfigured, or if there is
> something that I can change so that this spike doesn't occur.

So is it the "auth" process or "auth worker" process? What if you add:

> passdb {
>  driver = shadow
> }
> userdb {
>  driver = passwd
args = blocking=yes
> }

does that move the CPU usage from "auth" to "auth worker" process? Is it using /etc/shadow and /etc/passwd files? Are they large? Do you have enabled other weird stuff in /etc/nsswitch.conf (and were there some other files related to them as well?)