choosing a file system

[Vincent Fox]

We run Solaris 10 on our Cyrus mail-store backends.
The mail is stored in a ZFS pool.  The ZFS pool are
composed of 4 SAN volumes in RAID-10.  The active
and failover server of each backend pair have "fiber multipath"
enabled so their dual connections to the SAN switch ensure
that if an HBA or SAN switch fails there is no downtime.

Once a month we run a scrub while the systems are online.
Never having to run fsck EVER AGAIN is a good thing.
The scrub is run during a weekend and not during a backup
window to be paranoid since it does keep the disks busy
for some hours but it never impacts performance.

Using ZFS also allows us easy & CHEAP snapshots.
We keep 14 days worth of snapshots in the pool and
that handles 99% of restore requests.  We run backups
to tape once a week from the most recent snapshot also.

LALOT Dominique wrote:
> Hello,
>
> We are using cyrus-imap for a long time. Our architecture is a SAN 
> from EMC and thanks to our "DELL support" we are obliged to install 
> redhat. The only option we have is to use ext3fs on rather old 
> kernels. We have 4000 accounts for staff and 20000 for students
> The system is rather fast and reliable. BUT..
>
> Once, there was a bad shutdown corrupting ext3fs and we spent 6 hours 
> on an fsck.
> Next we discovered that our backup system was going slower and slower. 
> We just pointed out that it was due to fragmentation, and guess what, 
> there's no online defrag tool for ext3.
>
> I'm looking for other solutions:
> ext4fs (does somebody use such filesystem?), xfs
> zfs (but we should switch to solaris or freebsd and throw away our 
> costly SAN)
> use a NetApp Appliance (are you using such a device?, NFS seems to be 
> tricky with cyrus..)
>
> Thanks for your advice
>
> Dom
>
> -- 
> Dominique LALOT
> Ingénieur Systèmes et Réseaux
> http://annuaire.univmed.fr/showuser?uid=lalot
> ------------------------------------------------------------------------
>
> ----
> Cyrus Home Page: http://cyrusimap.web.cmu.edu/
> Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki
> List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html