On Mon, 2006-12-04 at 15:11, Anton Melser wrote:
> Hi,
> I am just starting at a company and we are inheriting a previously
> built solution. It looks pretty good but my previous experience with
> pg is seriously small-time compared with this...
OK, how you set up RAID depends largely on how you'll be using your
database.
First things first though...
Since your vacuum looks to have been turned off for a while, I'd
recommend doing a vacuum full and a reindexdb and see if that helps,
then either schedule regular backups or let autovacuum do it from now
on.
After that, you can worry about setting up your RAID. Generally RAID 10
is better for transactional dbs (airline reservations, e commerce
etc...) while RAID5 or 50 is often better for large reporting
databases. This depends on your controller of course. Some can layer
RAID levels and some can't, and some that can probably shouldn't try
(i.e. their performance is really bad when layering RAID levels.)
Putting your xlog on physically separate disks helps IF you are writing
enough to justify it. If you run bulk updates at 2 in the morning and
the rest of the day <0.1% of your db activity is insert / update then
you would be better spending your time elsewhere.