Thanks for that Josh.
I had previously understood that ext3 was a bad thing with PostgreSQL and I
went way above and beyond to create it on an Ext2 filesystem (the only one
on the server) and mount that.
Should I undo that work and go back to Ext3?
Jeff
----- Original Message -----
From: "Josh Berkus" <josh@agliodbs.com>
To: "Jeffrey D. Brower" <jeff@pointhere.net>; "Andreas Kostyrka"
<andreas@mtg.co.at>
Cc: "Bruce Momjian" <pgman@candle.pha.pa.us>;
<pgsql-performance@postgresql.org>; "Shankar K" <shan0075@yahoo.com>; "eric
soroos" <eric-psql@soroos.net>
Sent: Wednesday, April 02, 2003 3:05 PM
Subject: Re: [PERFORM] ext3 filesystem / linux 7.3
> Jeff,
>
> > How all of that works WITH and/or AGAINST PostgreSQL and what metadata
> > REALLY means is my bottom line quandary. Obviously that is where
finding
> > the warm and fuzzy place between speed and safety is found.
>
> For your $PGDATA directory, your only need for filesystem journaling is to
> prevent a painful fsck process on an unexpected power-out. You are not,
as a
> rule, terribly concerned with journaling the data as PostgreSQL already
> provides some data recovery protection through WAL.
>
> As a result, on my one server where I have to use Ext3 (I use Reiser on
most
> machines, and have never had a problem except for one disaster when
upgrading
> Reiser versions), the $PGDATA is mounted "noatime,data=writeback"
>
> (BTW, I found that combining "data=writeback" with Linux LVM on RedHat 8.0
> resulted in system-fatal mounting errors. Anyone else have this
problem?)
>
> Of course, if you have a machine with a $60,000 disk array and disk I/O is
> unlimited, then maybe you want to enable data=journal just for the
protection
> against corruption of the WAL and clog files.
>
> --
> -Josh Berkus
> Aglio Database Solutions
> San Francisco