[Dovecot] Great time savings backing a mdbox versus Maildir

[Jan-Frode Myklebust]

On Tue, Feb 08, 2011 at 08:42:40AM +0100, Javier Miguel Rodríguez wrote:
> 
>     I am writing to this mailing list to thanks Timo for dovecot 2 &
> mdbox. We have almost 30.000 active users and our life was sad with
> Maildir & backup: 24 hours for a full backup  with bacula (zlib
> enabled maildirs, 1.4 TB). After switching to mdbox, the backup time
> is under 12 hours ! Instead of backing 17 millions files, with mdbox
> our backup is only of 1 million files, and that speeds up a lot the
> backup operation.

Oh.. I envy you. Will probably need to do the same at some point, but
I'm having problems understanding how we will ever be able to make the
transition. Too many files -- too many users..

How long did it take to convert from maildir to mdbox, how much downtime ?

Do you have a clustered setup, or single node? I'm wondering how safe
mdbox will be on a clusterfs (GPFS), as we've had a bit of trouble with
the index-files when they're accessed from multiple nodes at the same
time (but that was with v1.0.15 -- so we should maybe trust that such
problems has since been fixed :-)


  -jf