[Dovecot] issues migration from dovecot 1.2 to version 2

[Timo Sirainen]

On 20.3.2012, at 9.35, Rajesh M wrote:

> i migrated my email server with around 5000 users from dovecot version 1.2
> to version 2
> 
> i have two separate 2 tb hdd's storing webmail data of these users.

You mean you simply upgraded the Dovecot version, the server is exactly the same?

> the load on the server goes very high over 100 during peak load times and
> the imap connections get dropped frequently, webmail becomes very slow.

There shouldn't be much performance difference between v1.2 and v2.x.

> in the dovecot log file i get errors as such
> 
> Warning: Maildir /homebackup/domains/xxxx/xxxx/Maildir/.ALL_INBOX MAIL:
> Synchronization took 71 seconds (20 new msgs, 0 flag change attempts, 0
> expunge attempts)

This simply means that the disk IO usage is very high.

> i am a bit confused as to what settings are to be done for a very busy server

Show dovecot -n output of the new server, and if you have the old configuration available that could be helpful also to compare their differences.