[CentOS] Backup solution to backup /var/spool/imap above 150GB data

[Gavin Carr]

On Wed, Feb 24, 2010 at 10:38:32AM +0100, David Hrbáč wrote:
> Dne 24.2.2010 10:00, Agnello George napsal(a):
> > We have  an issue with one of our clients , they have a mail server with
> > the  /var/spool/imap partition as 150 GB . They need to take differential
> > backup on to /backup partition ( a different HDD  of total 250 GB space )  .
> > We have tried dar , rsync, rdiff and impasync . But its is not sufficing the
> > need as to take a lot of time and consumes a lot of I/O .
> > 
> > Is there any back up solution that you can think of , that can work in this
> > situation  - open source or proprietary
> 
> Is seems to me, that you are using mbox format. So, differential backup
> is hard to achieve. Migrate to maildir, every mail is a file, easy to
> backup differentially.

rsync and rdiff should handle mbox format okay though. Though I agree Maildir 
is generally nicer for differential backups.

Agnello, how long is "a lot of time"? A backup is always going to have to walk
the entire tree and checksum (or at least stat) every file, so there's a minimum
cost you're always going to have. How long does a 'find /var/spool/imap -ls' 
take, for instance?

You might want to try brackup (http://code.google.com/p/brackup/). For very 
large trees of relatively small files it seems to significantly out-perform 
rsync-based backups. I've got brackup packages in my repository (see 
http://www.openfusion.net/linux/openfusion_rpm_repository).

Cheers,
Gavin