Re: PostgreSQL on Solaris 8 and ufs

On Tue, 2005-03-22 at 14:44 -0600, Brandon Metcalf wrote:
> We've recently moved our pgsql installation and DBs to a Solaris 8
> machine with striped and mirrored ufs filesystem that houses the DB
> data. We are now seeing terrible performance and the bottleneck is no
> doubt disk I/O.
>
> We've tried modifying a tunables related to ufs, but it doesn't seem
> to be helping.
>
> Is there anything we should be looking at that is specifically related
> to ufs filesystems on Solaris 8 or possibly something in general that
> would improve performance?
>
> Thanks.
>

What are you using to create your raid? You say it is "no doubt disk
I/O" - does iostat confirm this? A lot of performance issues are related
to the size of the stripe you chose for the striped portion of the
array, the actual array configuration, etc. I am assuming you have
looked at system variables such as autoup and the likes? What tweaks
have you done?

Also, are your pg_xlog and data directories separated onto separate
volumes? Doing so will help immensely. What are you using to measure
performance?

Sven