Re: partition question for new server setup

On 4/28/09 5:02 PM, "Whit Armstrong"  wrote:

> are there any other xfs settings that should be tuned for postgres?
> 
> I see this post mentions "allocation groups."  does anyone have
> suggestions for those settings?
> http://archives.postgresql.org/pgsql-admin/2009-01/msg00144.php
> 
> what about raid stripe size?  does it really make a difference?  I
> think the default for the perc is 64kb (but I'm not in front of the
> server right now).
> 

When I tested a PERC I couldn't tell the difference between the 64k and 256k
settings.  The other settings that looked like they might improve things all
had worse performance (other than write back cache of course).

Also, if you have partitions at all on the data device, you'll want to try
and stripe align it.  The easiest way is to simply put the file system on
the raw device rather than a partition (e.g. /dev/sda rather than
/dev/sda1).  Partition alignment can be very annoying to do well.  It will
affect performance a little, less so with larger stripe sizes.

> -Whit
> 
> 
> On Tue, Apr 28, 2009 at 7:40 PM, Scott Carey  wrote: