UNIX for Dummies Questions & Answers

Newbie, so bear with.

Have a dual boot: XP and OpenSuse 12.1, both are on separate discs.

I want to add a further disc, on which to run AVLinux.

When I connect up the disc, Boot stalls, with Grub error number 22. And works OK if I again disconnect the disc.

Have completely erased all partitions on disc using Parted Magic: it shows as 100% unallocated. Boot order (in BIOS) set not to boot this ahead of the two already existing.

Why does it do this? What can I do about it?

Sounds like the BIOS order is changing, regardless... Try swapping the cables and changing the order back in the BIOS itself.

Thanks for ever so prompt response. I will give that a go.

---------- Post updated 22nd Mar 2012 at 03:29 AM ---------- Previous update was 21st Mar 2012 at 09:38 PM ----------

Tried that, and still get number 22 error.

Grub seems to recognise this drive in preference to the others, no matter which channel I have it connected to, and irrespective of the boot order which I set in BIOS.

I have swapped out this HDD for a different unit, and alternate interface, (SATA in place of PATA) and system now boots OK.

I am no longer stuck, but from a learning point of view would still value knowing why this occurred, if anyone can tell me.

The system is loading the boot sector from one disk, but grub is using the wrong boot order and can't find its files. Adding the disk to SATA seems to mess up the boot order for your BIOS no matter what, quite strange.

Trying to think about this, (correct me if I am wrong) the BIOS component must be functioning correctly: for me to see such an error message, i.e.Master Boot Code being read from first (XP) drive, followed by execution then being passed to second (OpenSuse) drive from which Grub Boot is beginning execution.

With only two drives (1st is PATA, 2nd is SATA) Boot functions successfully.

When I add a third drive:

Works OK if added unit is a SATA Drive.
Error 22, if added unit is a PATA Drive!

So it appears that, in the last (3rd Drive PATA) arrangement, Grub ceases to search for its files on its own disc, searching the newly added disc instead!

I have tried looking in the on-line Grub Tutorial, but did not see anything to indicate why this should be happening. I would be grateful if anyone can give me a steer on where to look for more information.

On second thought, it could be problems with /boot/grub/device.map

If it doesn't match the BIOS order anymore, it could end up deciding hd0 is the wrong drive.

Thanks again, looks like you've nailed it.

Googling Grub device map yielded: "GRUB will get the order wrong if you exchange the boot sequence between IDE and SCSI in your BIOS."

I seem to recall from previous OpenSuse (11.4) that it treats SATA as SCSI.