Re: ZFS vs. UFS

On 24/07/2012 14:51, Laszlo Nagy wrote:
>
> Hello,
>
> Under FreeBSD 9, what filesystem should I use for PostgreSQL? (Dell
> PowerEdge 2900, 24G mem, 10x2T SATA2 disk, Intel RAID controller.)
>
> * 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 server.
> * 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.
>
> 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.