[Dovecot] Migration questions...

[Phillip Macey]

On 14/05/2009 5:11 PM, Steffen Kaiser wrote:
> On Wed, 13 May 2009, Richard Hobbs wrote:
>> The main complaint we have from users is that their IMAP Inbox, with
>> 5000 emails in it takes ages to appear, and no amount of coaxing will
>> convince them to split their inbox into multiple folders.
>
> Oh, we serve Maildir via Dovecot IMAP and 5000 messages per folder are 
> a wimp. Problems start if the user:
We are having some performancec issues on our server at the moment - all 
I can put it down to is the large size of some maildirs. Eg. `ls -ld 
Maildir/cur` might show a directory >20Mb in size for some of our users 
(20-30k emails).
(Performance issues == everything is running ok then all of a sudden 
load avg goes through the roof, system cpu time goes crazy. Reading mail 
grinds to a halt. Then everything recovers just as suddenly and the load 
avg gradually returns to normal levels)
> a) hits a 2GB limit on a mailbox in the mail client,
>
> b) try to move all their 20'000+ messages at once to an archive folder 
> once a year, when their quota limit is exceeded.
This generally causes us problems as well..

>> With maildir, and especially dovecot, this problem effectively
>> disappears! That's the theory anyway, right?
Theory is wonderful when it works :-)
I dont know for sure if our problems are caused by what I mentioned 
above, but it might be worth keeping it in mind.

-- 
Thanks,
  Phill Macey (CiSRA IT Services)