[Dovecot] Production server migration from mbox to maildir ( need advice )

[Rick Romero]

On Fri, 2009-02-13 at 10:05 -0800, Seth Mattinen wrote:
> Proskurin Kirill wrote:
> > Frank Bonnet wrote:
> >>> I use Debian amd64 with maildir. It works. Nothing really to say about
> >>> it. It's never given me any trouble and nobody ever complains about
> >>> performance. Easy to restore specific messages from backups when
> >>> customers accidentally delete messages.
> >>>
> >>> ~Seth
> >>
> >> Thank you Seth :-)
> > 
> > But with your storage you must think about backup strategies.
> > Rsync + maildir = many time
> > 
> 
> The other option is LVM snapshots or a filesystem that has snapshots
> like ZFS. Just don't use ext3 with snapshots on a busy server - it's a
> horrible performer because it's block-based. Extent-based ones like xfs
> perform much better and you can "freeze" an xfs filesystem so the
> snapshot is consistent.
> 
> This is about MySQL but it has some good information:
> http://www.mysqlperformanceblog.com/2009/02/05/disaster-lvm-performance-in-snapshot-mode/
> 
> And this Ars article describes the basic snapshot procedure for those
> unfamiliar with it:
> http://arstechnica.com/open-source/news/2004/10/linux-20041013.ars


In addition, the rsync 'slowness' issue can be alleviated by breaking it
up into smaller pieces (And version 3.0 is helpful).  Since many
files/directories on a single volume has been an issue for many
filesystems for many years, some sort of directory management is usually
already in place which you can use to break up rsync into smaller
chunks.

Rick