Grub and USB CDROM drives

[Scottie]

Hi,

Great forum. Hoping maybe someone can give me some grub pointers here.

I've built a custom Linux install CD with my own initrd and the grub El Torito stage 2 loader image. It works great on a variety of "standard" PCs. However, I'm having trouble getting it to work on an IBM BladeCenter. This chassis utilizes a CD-ROM/Floppy module that can be switched between blades by simply pressing a button on the selected blade. Word from IBM (I'm still waiting to hear back from them on this), is that the CD is a USB device.

When I boot a blade from this CD, grub comes up in command line mode and that's it. No boot menu, etc. Grub stage 1 appears to be loading off the CD, but then gets no further -- apparently because my boot image (Stage 1.5/Stage 2) has no idea where the CD is. I'm guessing that my boot image (specified as eltorito_stage2 to mkisofs) is not at the "expected" location because this is a USB CD, rather than IDE.

Anybody got a clue as to how I can fix this? I've googled the question and found all kinds of postings describing the same problem -- but no one seems to have a solution! Not much in the Grub Manual either. And the stage 1/stage 2 code is definitely for BIOS experts only, which I'm not.

I know this is do-able because the SuSE 9.1 stock CDs work fine on this platform. I'm just missing the "USB link" or something. Any help would be much appreciated!

[Nerderello]

does grub support the CDROM's file system type? It's been quite a while since I look at this, but I don't think it does.

Anyway, that's one possible area for you to have a look at.

good luck

Nerderello

[Scottie]

Yes, it does. The filesystem type is iso9660.

As I stated above, this CD works fine on systems with an IDE CD-ROM drive. It seems to be USB (or the BladeCenter BIOS) that is the problem....

[Nerderello]

is this anything to do with it ? -

http://www.gnu.org/software/grub/man...table%20CD-ROM


Nerderello

[ivi]

hi - think our problem is known ...

http://savannah.gnu.org/bugs/index.p...&item_id=11723

-ivi

[Scottie]

Thanks, that last post indicates that the bug has been filed with the Grub crew. However, the problem remains.

The post before that is not the solution -- we already have a bootable CD. The problem is that it does not boot correctly on a USB CD-ROM drive.

Since grub appears to be the problem, we're now trying isolinux. No luck so far.... will post the solution if we discover it.

[Scottie]

Got it. ISOLINUX works. It took many iterations to get it to fly, so here's a summary:

Create a directory that reflects how the CD will look. That directory should contain a directory called isolinux. Within isolinux, you must have the following:

• kernel
  initrd
  isolinux.bin
  isolinux.cfg

Other files can exist wherever; e.g., we have assorted gzipped tar files that will be expanded to a hard drive by linuxrc (which lives in the initrd RAMdisk image).

Unless anyone knows better, the kernel and initrd names must be short simple file names. I had a kernel named "vmlinuz-2.6.8.1-smp" and nothing worked until I hard-linked "vmlinuz" to it and specified that in the isolinux.cfg file. Same for initrd.

Other than that, create your isolinux.cfg and build the ISO per the (sketchy) ISOLINUX documentation.

Thanks for the replies!