Re: Postgres on RAID5

Arshavir Grigorian <ag@m-cam.com> writes:
> I have a RAID5 array (mdadm) with 14 disks + 1 spare. This partition has
> an Ext3 filesystem which is used by Postgres. Currently we are loading a
> 50G database on this server from a Postgres dump (copy, not insert) and
> are experiencing very slow write performance (35 records per second).

What PG version is this?  What version of pg_dump made the dump file?
How are you measuring that write rate (seeing that pg_restore doesn't
provide any such info)?

> Postgres is installed from the Debian package and uses
> all the configuration defaults.

The defaults are made for a fairly small machine, not big iron.  At a
minimum you want to kick shared_buffers up to 10K or more.

            regards, tom lane