new server motherboard with SATA II

[Danny Carroll]

Jeremy, thanks for your response.

Jeremy Chadwick wrote:
> 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.

I do have a board with an ICH10 chipset but the SATA drives are detected 
as UDMA-33.

I guess the ICH* chipsets would not support AMD64, being an intel chip.

> 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).

Yeah, I'm not so keen of the modern trend to have on-board raid.  I'd 
rather keep it simple and let FreeBSD handle it.  Root disk will not be 
raid at all.

> 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.

Hmmm, some people say nforce4 chipsets are cool, some not...  It's hard 
to know which way to go.

> 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).

I've seen it on old ATA hardware.

> 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.

I thought that the 2gb limit was less of a problem for AMD64 because of 
the addressing used.

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

We'll like I said, I'd be willing to jump on a list and provide info etc 
about my setup.  I plan to have it running on a test bench with lots of 
IO for a week or so before I start using it.  Even then the data will 
not be critical so if it breaks then I can rebuild without hassle. 
System disk will be UFS2 to keep it simple...

I've got it running on desktop hardware (ASUS P5Q board with ICH5) while 
I wait for a decision on a permanent Motherboard.  With this setup I see 
about 60mb write speeds on ZFS across 5 disks.  I've done the basic 
tuning suggested in the Wiki.  One thing I notice is that the CPU is 
used for 30% on Interrupts.  It was firewire first, so I disabled it in 
the BIOS, then it went to UHCI so I disabled all USB ports.  Now it is 
on the ATA controller.  All of this was on the same interrupt (19).

I'm thinking of getting a couple of Promise SATA-300 TX4 IO cards 
(non-raid).  Perhaps that will offload the CPU.

-D