On Wed, Aug 21, 2013 at 02:18:52PM +0200, Andrea gabellini - SC wrote:
So you are using the same config I'm testing. I forgot to write that I use maildir.
I would strongly suggest using mdbox instead. AFAIK clusterfs' aren't very good at handling many small files. It's a worst case random I/O usage pattern, with high rate of metadata operations on top.
We use IBM GPFS for clusterfs, and have finally completed the conversion of a 130+ million inode maildir filesystem, into a 18 million inode mdbox filesystem. I have no hard performance data showing the difference between maildir/mdbox, but at a minimum mdbox is much easier to manage. Backup of 130+ million files is painfull.. and also it feels nice to be able do schedule batches of mailbox purges to off-hours, instead of doing them at peak hours.
As for your settings, we use:
mmap_disable = yes # GPFS also support cluster-wide mmap, but for some reason we've disabled it in dovecot..
mail_fsync = optimized
mail_nfs_storage = no
mail_nfs_index = no
lock_method = fcntland of course Dovecot Director in front of them..
-jf