[CentOS] Re: Opteron Mobo Suggestions

[Bryan J. Smith <b.j.smith@ieee.org>]

From: Kirk Bocek <t004 at kbocek.com>
> Yes, I understand. I also don't have an unlimited budget
> If I can get most of the benefit without needing a $300-800
> add-on, that's a big plus.

You're talking about an $500-600 mainboard.
Then you're talking about $500-800 _per_ dual-core CPU.
And then you're gotta factor in the Registered ECC RAM costs.

And you're worried about a $125 (3Ware Escalade 8006-2) or
$300 (3Ware Escalade 8506-4) controller?  Furthermore, the
SATA on the nForce MCP is typically only a single, 133MBps
PCIe x1 channel.  You'll get 533MBps out of the 8506-4
in a PCI slot at 64-bit @ 66MHz.

> I conceptually understand iSCSI, but how would I use a GbE
> NIC in a backup solution?

What do you think iSCSI is?  It's storage over IP, but just with
an additional a host processor in the GbE to off-load overhead.

If you don't have the money for a HBA GbE, then just do
straight GbE.  Build an out-of-band IP network segmented off
on a 2nd GbE connection in each system.

[ HINT:  I'm exploring the issues of real-time backup and
discuss near-line storage, virtual tape libraries and, in a
future article after that, out-of-band networks and "cheap"
SANs.  All from the standpoint of a sysadmin, and not so
much network/storage engineering. ]

> Don't forget that a backup solution would depend on 
> hot-pluggability. That's why I was thinking of USB/IEEE-
> 1394.

Mistake on a server.  You don't want to hot-plug
consumer interconnects.  One issue, bam!  Kernel panic.

Use an out-of-band IP network over a 2nd GbE connection
to what you need elsewhere on the network.  I have been
recommending this where cost is a factor.

> Cool, I will take a look at HP's offerings. Do you have any
> motherboards alone that you would recommend?

It's difficult because of the limited designs.  A lot of
mainboards "cut corners" for cost considerations.  Even
the Tyan 4885 puts _all_ I/O on _one_ CPU.  The HP
DL585 follows the AMD reference.



--
Bryan J. Smith   mailto:b.j.smith at ieee.org