To: pgsql-performance@postgresql.org
From: Ivan Voras <ivoras@freebsd.org>
Subject: Re: ZFS vs. UFS
Date: Tue, 24 Jul 2012 15:18:29 +0200
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Message-ID: <jum7b5$gs6$1@dough.gmane.org>
References: <500E9A3B.3070609@shopzeus.com>
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On 24/07/2012 14:51, Laszlo Nagy wrote:
>=20
>   Hello,
>=20
> Under FreeBSD 9, what filesystem should I use for PostgreSQL? (Dell
> PowerEdge 2900, 24G mem, 10x2T SATA2 disk, Intel RAID controller.)
>=20
>  * ZFS is journaled, and it is more independent of the hardware. So if
>    the computer goes wrong, I can move the zfs array to a different ser=
ver.
>  * UFS is not journaled. Also I have to rely on the RAID card to build
>    the RAID array. If there is a hw problem with it, then I won't be
>    able to recover the data easily.
>=20
> I wonder if UFS has better performance or not. Or can you suggest
> another fs? Just of the PGDATA directory.

Hi,

I think you might actually get a bit more performance out of ZFS,
depending on your load, server configuration and (more so) the tuning of
ZFS... however UFS is IMO more stable so I use it more often. A hardware
RAID card would be good to have, but you can use soft-RAID the usual way
and not be locked-in by the controller.

You can activate softupdates-journalling on UFS if you really want it,
but I find that regular softupdates is perfectly fine for PostgreSQL,
which has its own journalling.


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