[Dovecot] Performance-Tuning

[Henrique Santos Fernandes]

Jan-Frode

Wich clustered filesytem do you have?

I used to have ocfs2 but had problems with performance. So had to get back
to ext4 and it solve the performance problem...

My ocfs2 setup had some problems... but still..
Some numbers:

OCFS2
1TB of maildir files.
Full backup 36 Hours
Incremental 15 hours

Ext4
1TB of maildir files.
Full backup 16 Hours
Incremental 1 hour

Same LUN on storage.


[]'sf.rique


On Mon, Nov 14, 2011 at 4:42 PM, Stan Hoeppner <stan at hardwarefreak.com>wrote:

> On 11/14/2011 4:27 AM, Jan-Frode Myklebust wrote:
>
> > Agree. A non-clustered fs should give you better performance, and
> > probably also be more reliable, if you can live with the SPoF and
> > full downtime during patching/upgrades/maintenance. But I would expect
> > xfs to be a better choice than ext*.
>
> Depends on the workload characteristics and how well the XFS filesystem
> is tuned to the storage hardware.  If setup properly, using many
> allocation groups with fast spindles, a decent amount of BBWC, and a
> high concurrency maildir workload (dozens to hundreds of delivery and
> IMAP operations), XFS will runs circles around EXTx as it can
> create/write/read to every AG in parallel.  Much of EXT4's operation is
> still serialized.  This is why XFS outruns all other filesystems in the
> highly parallel mail workload benchmarks I posted previously, EXTx by a
> factor of 2-3.
>
> For smaller hosts that don't see parallelism, for example SOHO servers,
> XFS will likely be slower than EXTx as the workload will be serialized.
>
> --
> Stan
>