designing new freebsd server for amd64 arch

[Ketrien I. Saihr-Kesenchedra]

On Tue, Apr 19, 2005 at 03:19:00PM -0600, Ken Gunderson wrote:

> I loved IBM drives years ago, but started having too many issues when
> they started cutting a few too many coreners.  The things just started
> dying prematurely.  Hitachi drives also have a fairly bad rep amongst
> serveral consultants I know.  

I'm reminded of a Demotivators poster; "There's good money to be made in 
prolonging the problem," to paraphrase slightly. e.g., yes, I'm calling them
out. Observed and demonstrated statistical failure rates on the Hitachi 10K174
and 15K73 line are typically lower than Seagate and Fujitsu. Except when you
get some kid slapping parts together and calling it a box. At which point, all
failure rates go out the door, because the whole thing is a ticking time bomb.
 
> To summarize, for the K8S Pro, it seems your suggestion would be to stay
> away from the pci- x adapters all together??  Which leaves something
> like the Adaptec 2120 or the LSI 320-1LP (for a 2U rackmount system).
> Can anyone give me some guidance if either of these has advantages/
> disadvantages under fbsd amd64?

No, PCI-X adapters on the A (133MHz) bus, which is where Tyan jammed all the
onboard peripherals. This creates major timing migraines, especially at a 
133MHz clock. The B bus (66MHz) does not have this problem, which leaves you
with anything that can downclock to 66MHz. If it's PCI-X compliant, it can
downclock to 66MHz. Hell, the Ultra320-2X can step down to PCI32/33. (I've 
actually done this for testing.) The catch is that you lose the bus bandwidth
you may need for extremely intensive disk I/O. Of course, you really aren't
going to be in any trouble until you get up into 1Gbit-2Gbit FC-AL. The 320-2
here does over 100MB/s read and 100MB/s write on 15K73's with RAID1. If you 
need more than that, you should probably start looking at an Iwill H8501 and
it's triple 8131 setup.

As far as advantages/disadvantages - last I'd heard, aac(4) is not 64-bit 
clean, nor is asr(4). Which means you aren't going to be running them on
amd64. amr(4) is 64bit clean and >4GB safe, so really, it's the only choice.
Well, besides Qlogic FC (isp(4)), but I don't know if anyone's even tested
that. 

-ksaihr