Cyrus Backup Strategy

[Igor Brezac]

On Fri, 13 Jun 2003, pnelson wrote:

> On Fri, 2003-06-13 at 12:11, Igor Brezac wrote:
> > On Fri, 13 Jun 2003, pnelson wrote:
> >
> > > On Fri, 2003-06-13 at 11:29, John Alton Tamplin wrote:
> > > > pnelson wrote:
> > > >
> > > > >My last thing to do prior to converting to production is a backup
> > > > >strategy.  I have been doing this with tar something like:
> > > > >
> > > > >tar -C /var/lib    -czf lib-<date>.tar.gz    imap
> > > > >tar -C /var/spool  -czf spool-<date>.tar.gz  imap
> > > > >tar -cf cyrus-<date>.tar
> > > > >
> > > > >This is producing a pretty big file(s):
> > > > >
> > > > > lib-<date>.tar.gz    ->   2.2M
> > > > > spool-<date>.tar.gz  ->  11.0M
> > > > >
> > > > >and ultimately
> > > > >
> > > > > cyrus-<date>.tar     ->  13.5M
> > > > >
> > > > >and I was thinking maybe there is a better way that someone else has
> > > > >come up with.  Anyone doing backups a different way?
> > > > >
> > > > Are you then dumping these files to tape?  Otherwise, just having
> > > > another copy on disk doesn't protect against many potential causes of
> > > > data loss.
> > >
> > > Yes dumping to removable medium.
> > >
> > > > We just backup the mail files normally with Veritas Netbackup (be sure
> > > > to disable true image restore with the millions of files), with the only
> > > > custom bit being to dump a copy of the mailbox list to a text file
> > > > before the backups run (this is a precaution since we are backing up
> > > > structured database files without synchronization with the program
> > > > writing them, so there is no guarantee the resulting backup is useful).
> > > > Our full backup for all Cyrus files is 98G and 4.2M files, taking 5-8
> > > > hours depending on other data hitting the tape drives.  Daily
> > > > incremental backups average 1-3G and 10-30k files.
> > >
> > > So a cyrus backup needs to contain:
> > >
> > > /var/spool/imap
> > > /var/lib/imap/mailboxes.db
> > >
> > > to be useful as a backup, right?  With these to things I can recover...
> > > I'm making sure I understand this completely.
> >
> > I am not sure what your directory structure looks like, but you need to
> > make sure to backup sieve and quota directories.
> >
> > Your procedure may require hand recovery after restore before the mail
> > store is usable.  I recommend using filesystem snapshot (i assume you do
> > not stop the mail server during backup) before performing backup.  This
> > will make your backup 'sane.'
> >
> > > How do you dump mailboxes to/from text?
> > > What is the restore process?
>
> Good point.  So the latest process would be:
>
> So a cyrus backup needs to contain:
>
>  su cyrus -c "ctl_mboxlist -d" > mailboxes-<date>.txt

This is not neccassary, but not a bad idea.

>  /var/spool/imap
>  /var/lib/imap/quota
>  /var/lib/imap/user
>  /var/lib/imap/sieve
>
> Not sure how the filesystem snapshot works?

On solaris do 'man fssnap'.  veritas filesystem supports the snapshot
feature as does Linux (at least the newer versions), I am not sure which
filesystem.  Basically, this feature provides a temporary stable and
read-only view (snapshot) of a filesystem.  The writes occur on a separate
filesystem or device.

-- 
Igor