[Dovecot] Compressing existing maildirs

[Jan-Frode Myklebust]

On Fri, Dec 30, 2011 at 06:38:28PM -0600, Stan Hoeppner wrote:
> 
> Roger that.  Good strategy.  You using SAN storage or local RAID?  What
> filesystem do you plan to use for the new mailbox location?  What OS is
> the Dovecot host?

IBM DS4800 SAN-storage. Filesystem is IBM GPFS, which stripe all I/O
over all the RAID5 LUNs it has assigned. Kind of like RAID5+0. To guard
against disaster if one RAID5 array should fail, we plan on replicating
the filesystem metadata on different sets for LUNs.

OS is RHEL (currently RHEL4 and RHEL5, but new servers are implemented
on RHEL6).

> Lastly, how many users you have?  Sorry for prying,

I'd rather not say.. but we're an ISP, with about 250.000 residential
customers and multiple mailboxes per customer.

> I'm always really curious about system details when someone states they
> have 12TB of mailbox data. ;)

	$ df -h /usr/local/atmail/users
	Filesystem            Size  Used Avail Use% Mounted on
	/dev/atmailusers       14T   12T  2.1T  85% /usr/local/atmail/users
	$ df -hi /usr/local/atmail/users
	Filesystem            Inodes   IUsed   IFree IUse% Mounted on
	/dev/atmailusers        145M    109M     37M   75% /usr/local/atmail/users

Looking forward to reducing the number of inodes when we finally move to
mdbox.. Should do wonders to the backup process.


  -jf