new server motherboard with SATA II

[Jeremy Chadwick]

On Fri, Jun 27, 2008 at 12:30:51PM +1000, Danny Carroll wrote:
> Hello all,
>
> I'm looking to set up a file server at our office.  It's a small office  
> so price is a concern.  Performance is also going to be important.
>
> The data will be replicated from another site so integrity of the data  
> is not paramount.  For this reason I think I'll be able to run with ZFS.  
>  I see it as a good opportunity to contribute to getting ZFS stable and  
> non-experimental.
>
> What I am really concerned about is the SATA support.
>
> If I look at AMD64 as an arch, does anyone have any experience with good  
> IO chipsets that can do full SATA-300?
>
> I don't mind if it is a on-board or if I get a good controller card so  
> long as I can get decent performance out of the Seagate Barracuda  
> 7200.11 drives.

SATA150 and SATA300 both work just fine on FreeBSD, but its dependent
upon what chipset you go with.  I would strongly recommend you go with a
board/system that uses Intel's ICH7, 8, or 9 southbridge.  I have
extensive experience using these in production environments, and they
are very reliable, plus fast.  FreeBSD works quite well with them.

Second, I wouldn't bother considering using Intel MatrixRAID (which all
of the above chipsets support) for any sort of failover for your root/OS
disk, in case you're tempted to try it.  FreeBSD has bugs pertaining to
such support (see below Wiki URL for some examples).

Third, I cannot recommend nVidia chipsets, because there have been
numerous reports recently and in the past where the SATA disks are being
detected as UDMA33.  I believe there are some ATI/AMD chipsets which are
doing the same.  There is a rumour that the operational speed of the
disks is still SATA150/300, and just that FreeBSD is labelling the
negotiated speed wrong, but my recommendation is not to risk it.

Fourth, because you'll likely have multiple disks in a ZFS zpool, you
should probably be aware of the problem that haunts some users from time
to time (re: DMA errors).

http://wiki.freebsd.org/JeremyChadwick/ATA_issues_and_troubleshooting

> I'd be willing to go with intel arch although from a ZFS perspective it  
> sounds like AMD64 is better.

There was a recent discussion on developers@ (which is private) about
some topics, which eventually lead into a discussion about ZFS, tuning,
and a 2GB kmem limit in FreeBSD (which affects amd64 too).  I can't copy
the conversation/thread because developers@ has a strict "do not
disclose" policy.

We can discuss those topics separately here without issue -- I just mean
I can't copy/paste what's already been said on another list.

Just be aware you ***will*** need to tune ZFS on FreeBSD to make it
as reliable as possible.

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |