Re: Raid 10 chunksize

David Rees <drees76@gmail.com>

From: David Rees <drees76@gmail.com>
To: Scott Carey <scott@richrelevance.com>
Cc: Mark Kirkwood <markir@paradise.net.nz>, "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Date: 2009-03-25T02:04:42Z
Lists: pgsql-performance
On Tue, Mar 24, 2009 at 6:48 PM, Scott Carey <scott@richrelevance.com> wrote:
> Your xlogs are occasionally close to max usage too -- which is suspicious at
> 10MB/sec.  There is no reason for them to be on ext3 since they are a
> transaction log that syncs writes so file system journaling doesn't mean
> anything.  Ext2 there will lower the sync times and reduced i/o utilization.

I would tend to recommend ext3 in data=writeback and make sure that
it's mounted with noatime over using ext2 - for the sole reason that
if the system shuts down unexpectedly, you don't have to worry about a
long fsck when bringing it back up.

Performance between the two filesystems should really be negligible
for Postgres logging.

-Dave