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

[Urban Loesch]

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