[Dovecot] Very High Load on Dovecot 2 and Errors in mail.err.

[Javier Miguel Rodríguez]

I know that you are NOT running RHEL / CentOS, but this problem with
> 1000 child processes bit us hard, read this red hat kernel bugzilla
(Timo has comments inside):


https://bugzilla.redhat.com/show_bug.cgi?id=681578 

Maybe you are
hitting the same limit? 

Regards 

Javier 

El 20/05/2012 11:59, Urban
Loesch escribió: 

> Am 19.05.2012 21:05, schrieb Timo Sirainen:
> 
>>
On Wed, 2012-05-16 at 08:59 +0200, Urban Loesch wrote: 
>> 
>>> The
Server was running about 1 year without any problems. 15Min Load was
between 0,5 and max 8. No high IOWAIT. CPU Idletime about 98%.
>> .. 
>>

>>> # iostat -k Linux 3.0.28-vs2.3.2.3-rol-em64t (mailstore4)
16.05.2012 _x86_64_ (24 CPU)
>> Did you change the kernel just before it
broke? I'd try another version.
> 
> The first time it brokes with
kernel 2.6.38.8-vs2.3.0.37-rc17.
> Then I tried it with 3.0.28 and it
brokes again.
> On friday evening I disabled the cgroup feature
compleetly and until now 
> it seems to work normally.
> But this could
be because we have weekend and now there are not many 
> connections
active. So I have
> to wait until monday. If it happens again I will try
version 3.2.17.
> 
> On the other side it could be that the server is
overloaded, because 
> this problem happens only when there are
> more
than 1000 tasks active. Sounds strange for me, because it has been 
>
working without problems since 1 year
> and we made no changes. Also
there were almost more than 1000 tasks 
> active over the last year and
we had no problems.
> 
> thanks
> Urban