This Space for Rent

I tear my hair out so you don’t have to (aka Fun with computers)

I'm sure that someone else has already encountered this problem, because a lot of people use IBM servers, but when I looked online I didn't see any reasonable results for combinations of "x366", "rhel4", "panic", "double fault", and/or "Linux 2.6." So I'll relate my tale of woe in case someone else ends up sitting in front of a dead computer, wondering WTF is going on when their approved -by-IBM OS is dying during bootup on their spanking newish IBM x366.

What happened to me is that, after a couple of months of pasting the RHEL4u3 kernel onto the Linux distribution my corporate masters maintain (and a couple of months of having it load onto every IBM server I could get my hands on, which isn't very many because this is corporate American and it doesn't have to make sense as long as the government is Business Friendly(tm) [If the Soviet Union had been run as badly as the average US corporation, it wouldn't have taken 70 years to collapse under it's own weight.]) I handed a copy of it off to another group that was really really anxious to have a 2.6 kernel instead of the officially klunky 2.4 kernel we've been using up to now.

They upgraded their system to the 2.6 kernel, rebooted, and *wham*; dead server, bits rolling on the floor, and a panicky IT BROKE error report. Eventually, after a round or two of "what sort of machine?" requests, I discovered that they'd tried to install it on an IBM x366, which is modern enough to have some really bizarre interactions with the newer and more delicate versions of Linux out there.

Debugging this little feature was fun, because (a) every OS I could find that used a 2.6 kernel, from Redhat EL 4 to CentOS 4 (better for testing, because CentOS provides a "server CD" that you can use to install CentOS on a headless server; Redhat, even when you turn everything off, insists on installing every gui possible, and taking 4 CDs to do it) to really obscure mainline distributions like Knoppix, ended up with the same dead machine, and bits on the floor.

And in the end, it turned out to be a pretty trivial, if undocumented, fix. Apparently the x366 lets you set a processor mode in the bios, with two different settings (Special and Logical). And what's so special about special, you might ask? Well, if you're running a 2.4 kernel, there's nothing very special about it. But if you're running a 2.6 kernel, you get, for free, your dead servers and bits rolling on the floor.

If that isn't the desired behavior, change the processor setting to "logical" and the machine will boot up and act like a normal computer. (IBM has a web page that describes some things needed to make RHEL4 [and presumably other 2.6 kernels] stagger to life on an x366, but it doesn't say anything about special being really special.)

If you got here via a search engine, after watching your x366 fall over dead, you may consider yourself enlightened. And be thankful it's not an x3850 with a pci-X disk interface card that you're trying to install red hat onto.


Aiiiigh! I got here because I am trying to install RHEL4 onto an x3850 using the integrated drive controller, and I’m indeed tearing my hair out. Any pointers? Please? Heh. I’ve found the adp94xx driver from IBM (1.0.7-11 or some such), downloaded it, made a driver disk. I tried installing RHEL4 using the ‘linux dd’ boot option, and it asked for the driver disk - I gave it the driver CD, it swallowed it, asked if I had any others. I said no. I continued the install.

When I got to the ‘add drivers’ part, I found the adp94xx listed, and tried to select it, but the machine refused to admit that one was installed. It would install the general AHCI (?) drivers, but those wouldn’t find any drives, naturally.




jbz Wed May 2 11:26:29 2007

I don’t have a x3850 handy today, but if you’ve turned on the disk array you’ll need to load either the aacraid driver or the aacraid + adp94xx driver. It’s been a few weeks since I last played with one of the x3850s at work, so I don’t remember for sure which drivers have to be loaded for the disk array to work.

David Parsons Wed May 2 16:48:40 2007

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