Re: PostgreSQL on Solaris 8 and ufs

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.
>

I found that mounting the filesystem that contains the PGDATA directory
(probably only the pg_xlog directory in fact) without logging improved
things a great deal (assuming you are using logging that is...).

In addition changing the postgresql.conf parameter wal_sync_method from
the default of open_datasync to fdatasync improved  things a bit more.
However I seem to recall a posting suggesting the opposite! ...so feel
free to experiment and let us know!

Mark

P.s : original tests on Solaris 8,
http://archives.postgresql.org/pgsql-performance/2003-12/msg00165.php