I wonder then if the SCSI card that doesn't work has a fixed IO address that happens to fall within a memory address above 2 gig and you start having problems when ever that space is touched. I am just totally shooting in the dark, but it may be just that.

On 7/16/07, Steven Wagner <digital9ja@gmail.com> wrote:
Shawn Badger wrote:
> I am guessing it may be some bad memory. I know that CentSO can
> support much more than 4 Gig of memory. Get something like the system
> rescue cd and do a memory test to see if it makes it through.
>
> Also, remove the old 2 gig of memory and see if it works in that
> configuration. If it does, then you may even try to mix and match the
> chips. It is possible they sent you the wrong memory.
When we install CentOS to a SATA drive everything works fine and it sees
all 4 GB RAM and there aren't any problems. I think it's the SCSI card.
The card in the broken server is an Adaptec 2940W/2940UW. I found out
tonight that this same client has another server with us that is running
CentOS with 4 GB RAM, but the SCSI card in that system is an Adaptec
2940UW. hmmmm... I asked her if she could afford the downtime (15-20
minutes) for me to borrow that card and swap with the one in the broken
server. I'm still waiting to hear back on that.

At this point I am 98.9% sure it's something to do with the SCSI card.
Still, it's kind of weird that that card and those drives work perfectly
with 2 GB RAM, no? Maybe a firmware issue with the drives? Or the card?
>
>
>
> On 7/15/07, *Steven Wagner* <digital9ja@gmail.com
> <mailto: digital9ja@gmail.com>> wrote:
>
>     Technomage-hawke wrote:
>     > this may be a linux specific problem (I cannot be sure unless
>     the results can
>     > be duplicated with other linux distros).
>     >
>     > perhaps trying openBSD or OpenSolaris would work (fully
>     supported for that
>     > much ram and that hardware).
>     >
>     I've tried FreeBSD (and several other Linux distros) and it didn't
>     even
>     see the drives. I'm pretty sure that the problem is the card, but it's
>     still odd that it works fine with 2 GB RAM. Also, CentOS worked fine
>     with the SATA drive and all 4 GB RAM.
>     >
>     >
>     > TMH
>     >
>     > On Sunday 15 July 2007 21:57, Steven Wagner wrote:
>     >
>     >> I'm trying to upgrade a server from 2 GB of registered ECC RAM
>     to 4 GB.
>     >> The extra RAM was specifically purchased from the manufacturer
>     to be
>     >> identical to the existing modules. After installing the extra
>     RAM the
>     >> server panic'ed so we tried installing some other kernels, even
>     enabling
>     >> huge mem (64 bit) to no avail.
>     >>
>     >> I rebuilt the server with CentOS 4.4 Server CD with all 4 GB of RAM
>     >> installed. It panics when I try to boot with the full 4 GB
>     installed,
>     >> but boots fine when I remove 2 GB.
>     >>
>     >> The panic seems to happen when the SCSI card driver, aic7xxx,
>     tries to
>     >> enable the disc drives. The console error says:
>     >>
>     >> aic7xxx_dump returns 0x2002
>     >> Device offlined
>     >>
>     >> then a slew of SCSI I/O errors, the exec of init failed, then
>     the panic.
>     >> It seems weird that the card and the drives work fine with the
>     2 GB of
>     >> RAM...Anybody have any thoughts?
>     >>
>     >> TIA,
>     >>
>     >> Steve
>     >>
>     >> BTW, I installed CentOS 4.4 on this machine to a SATA drive and
>     it sees
>     >> all 4 GBs and works fine.
>     >> ---------------------------------------------------
>     >> PLUG-discuss mailing list -
>     PLUG-discuss@lists.plug.phoenix.az.us
>     <mailto:PLUG-discuss@lists.plug.phoenix.az.us>
>     >> To subscribe, unsubscribe, or to change your mail settings:
>     >> http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
>     >>
>     > ---------------------------------------------------
>     > PLUG-discuss mailing list -
>     PLUG-discuss@lists.plug.phoenix.az.us
>     <mailto: PLUG-discuss@lists.plug.phoenix.az.us>
>     > To subscribe, unsubscribe, or to change your mail settings:
>     > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
>     >
>     >
>
>     ---------------------------------------------------
>     PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us
>     <mailto:PLUG-discuss@lists.plug.phoenix.az.us>
>     To subscribe, unsubscribe, or to change your mail settings:
>     http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
>     <http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss>
>
>
> ------------------------------------------------------------------------
>
> ---------------------------------------------------
> PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us
> To subscribe, unsubscribe, or to change your mail settings:
> http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss

---------------------------------------------------
PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us
To subscribe, unsubscribe, or to change your mail settings:
http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss