[CentOS] DELL SC430 + CentOS 4.0 + SATA HDDs

[Bryan J. Smith]

Andrew Vong <andrewvong at finpress.com> wrote:
> Dear gurus,
> Three DELL SC430s were purchased by my company a few months
> back and I've been told that when they spoke with the DELL
> representatives, they were informed that these servers were
> fully RHEL 4.0 compatible.
> Specs of the servers:-
> - Pentium 4 - 2.8 GHz
> - 1 GB RAM
> - 2x 250GB SATA HDDs

Those specifications are not particularly enlightening.  What
is more relevant is the system and peripheral interconnect. 
Namely, in an Intel system, not just the memory controller
hub (MCH), but more importantly, the I/O Controller Hub
(MCH).

If this is a recent SC430 design, it is most likely the
ServerWorks, rebranded Intel, E7230 MCH with the optional
6702 PCI-X hub, with Intel's own ICH7R for SATA, legacy PCI,
etc...  Which brings me to ...

> I tried installing CentOS 4.0 on it but it doesn't seem to
> be able to detect any hard disks.

The ICH7R is most likely where your issue is.  

The ICH5+ has 2 modes, legacy ATA (including SATA) and the
Advanced Host Controller Interface (AHCI) mode.  I won't go
into what AHCI is, but without special OS-side software
drivers, it really doesn't give you much.  Although there is
a lot of work being done on the ICH5+'s AHCI support, I don't
trust it myself yet.  So you want to disable it, and have the
ATA+SATA run in a different mode.

Also, make sure the ICH7R is not configured for FRAID (fake
RAID).  Although newer DeviceMapper2 (DM2) developments can
now read the ICH5+ FRAID organization (at least for RAID-0/1
modes, but probably not the ICH7R's RAID-5, which sucks
anyway) and use the Linux kernel's own RAID logic, it's not
supported in the stock RHEL4 kernels/user-space packages (and
for good reason, long story).

> Has anyone out there successfully installed CentOS 4.0 on a
> Dell SC430? Please help. Your guidance is greatly
appreciated.

I don't know about the SC430, but if it has the 6702 chip
with PCI-X, I'd throw a $125 3Ware Escalade 8006-2LP on it. 
That will get you very reliable, _true_ hardware RAID-1.



-- 
Bryan J. Smith  b.j.smith at ieee.org http://thebs413.blogspot.com
---------------------------------------------------------------
"On the basis of the American view, which may be right, the
 success of the Iraqi political experiment is bound to provide
 a model to be emulated in Syria and in the various countries
 neighbouring Iraq" -- Nur-Al-Din, Al-Safir (Lebanon Periocial)