[Dovecot] dsync - how to speed up

[Timo Sirainen]

On Fri, 2010-09-17 at 15:23 +0200, Burckhard Schmidt wrote:
> dsync -v -u user mirror mbox:/old-homehome/~user:INBOX=/old-inbox/user
> 
> It works but it lasts "very long" time.
> For one mailbox with 2,4 Gb and nearly 200.000 emails it lasts 100 minutes.
> I would like to migrate 1.500 Gb - not possible in that way I think.
> 
> Are there any possibilities making it faster? May be not to generate 
> indices, ..., which could be done later during a first access by the user?

I'm pretty sure most of the time goes to creating the maildir files and
there's nothing that can be done to make it faster. Although you could
see if maildir_very_dirty_syncs=yes helps.

> Is it possible to run several dsync commands at the same time, of course 
> each one for a different user? (Ressources cpu and I/O system are 
> available.)

Sure.