Re: Postgres on RAID5

Tom Lane wrote:
> Arshavir Grigorian <ag(at)m-cam(dot)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)?

Sorry I missed the version. Both (the db from which the dump was created
and the one it's being loaded on) run on Pg 7.4.

Well, if the restore is going on for X number of hours and you have Y
records loaded, it's not hard to ballpark.

>
>
>>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
Will do. Thanks.

Arshavir