[Dovecot] Gluster / DRBD Anyone using either?

[Pawel Panek]

> Anyone using either Glusterfs or DRBD in their mail setup?  How is
> performance, manageability?  Problems?  Tips?
>
> Ed W
>

I tried to use Glusterfs (1.3.7) on mail cluster (qmail + dovecot), but for 
me it was terrifying mistake. The cluster is serving about 1,5k mail 
accounts. It was slow, unreliable and unstable. In bonnie++ tests it has 
nice values, about 65MB/s read and 30MB/s write (storage was ext3 on raid5 
on SATA2 drives on Intel E6750), but random seeks was slow (I think) 80 
seeks/s. This values are for single client (old one), and storage server 
could easily handle 3 simultaneous bonnie tests.
But when it comes to serve many small files it caused big load on cluster 
nodes, especially on older ones (P4 Northwood 3,0) causing poor performance. 
It showed up unstability getting segfaults in io-cache brick or even in 
client brick causing disconnecting the gluster mount.
I was using glusterfs modified fuse module (2.7.2glfs8). With fuse module 
shipped with 2.6.24 kernel I have some filesystem permissions issues causing 
reading wrong permissions of files.
DRBD should be right choice if you only need failover function.
I was using very minimal config and maybe I have misconfigured something.
Pawel