[Dovecot] enourmous amount of disc writes

[Rainer Sigl]

Hi Robert,
many thanks for your answer!
Yes I'm aware of the necessity to upgrade the complete system. Beside 
this I wanted to search for a quick solution. Upgrading the system 
entails many other things and is in my eyes not possible on the living 
system.
Did you ever measure the ioactiviy with iostat on your machine?
Please tell me the output values. Which hardware do you use?
I have a RAID5 with 3ware 7000 series.
Regards
Rainer


Robert Schetterer wrote:
> Rainer Sigl schrieb:
>> Hi List,
>> on my mailserver (exim4, dovecot 1.0.0, postgresql, ubuntu dapper, about
>> 500 users) I record an enourmous amount of disc writes (up to 18000
>> blocks written each second) in the time where most of users are active.
>> This IO activity causes wait-states on the disc interface (RAID5) and
>> finally slows down my mailmachine. Is there a explanation for these disc
>> writes respectively is there a possibility to minimize this activity.
>> Stopping Dovecot on this machine causes stopping most of the disc activity.
>>
>> Regards
>> Rainer Sigl
>>
>>
> Hi Rainer first you should upgrade to the latest stable of the 1.x branch
> or better 1.1.x, also dapper is very old perhaps try hardy
> 
> then retest, i run 2000 users on suse with dovecot 1.0.15 and mysql
> on sata 3ware hardware raid 1 500 GB on ext3 without any problems
> 

-- 
-----------------
Rainer Sigl,                      | email: sigl at mpe.mpg.de
MPI f. extraterrestrische Physik, | phone: +49 (89) 30000-3557
Postfach 1312,                    | fax:   +49 (89) 30000-3569
D-85741 Garching, Germany         | web:   http://www.mpe.mpg.de/~sigl/
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