Re: Configuration Recommendations

On Tue, Apr 24, 2012 at 4:56 AM, Jan Nielsen
<jan(dot)sture(dot)nielsen(at)gmail(dot)com> wrote:
> We are considering the following drive allocations:
>
>  * 4 x 15k SAS drives, XFS, RAID 10 on SAN for PG data
>  * 4 x 15k SAS drives, XFS, RAID 10 on SAN  for PG indexes
>  * 2 x 15k SAS drives, XFS, RAID 1 on SAN  for PG xlog
>  * 1 x 15k SAS drive, XFS, on local storage for OS

Is it established practice in the Postgres world to separate indexes
from tables? I would assume that the reasoning of Richard Foote -
albeit for Oracle databases - is also true for Postgres:

http://richardfoote.wordpress.com/2008/04/16/separate-indexes-from-tables-some-thoughts-part-i-everything-in-its-right-place/
http://richardfoote.wordpress.com/2008/04/18/separate-indexes-from-tables-some-thoughts-part-ii-there-there/
http://richardfoote.wordpress.com/2008/04/28/indexes-in-their-own-tablespace-availabilty-advantages-is-there-anybody-out-there/

Conversely if you lump both on a single volume you have more
flexibility with regard to usage - unless of course you can
dynamically resize volumes.

To me it also seems like a good idea to mirror local disk with OS and
database software because if that fails you'll get downtime as well.
As of now you have a single point of failure there.

Kind regards

robert

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