Kernel is not recognizeing boot location

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

I just added some hard drives to my system. Now when I boot up, the GRUB loads successfully. But when I pick Gentoo to load, I get a Kernel Panic- Kernel can not load. How can I fix this?

BradN · Posted: Wed Feb 27, 2008 10:29 pm Post subject:

Wait, grub can't load the kernel, or the kernel loads and then kernel panics (probably by not finding the root filesystem)?

If you added a hard drive, it may have changed the hard drive ordering for grub, since it numbers by the drives which are present, not including cdroms or not-present devices.

So, if you had, say a hard drive at hda, cdrom at hdc, and a linux drive at hdd, the linux drive would be (hd1). If you add a hard drive on hdb, then the linux drive would become (hd2).

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

The kernel loads and then kernel panics by not finding the root file system. Everything was until I added the extra HD's. The boot drive is still in the original location. Grub loads fine, and so does Windows XP. I have linux originally on hd0,1(Because Linux boot is on the second partition). Nothing has changed. The drive is still hd0, or else GRUB wouldn't boot, correct? I don't know exactly what to change since the drive is still hd0 and the boot partition is still hd0..

didymos · Posted: Wed Feb 27, 2008 11:12 pm Post subject:

OK, what about the kernel line in grub? I.e., the root="<blah>" part.
_________________
Thomas S. Howard

NeddySeagoon · Posted: Wed Feb 27, 2008 11:21 pm Post subject:

dman777,

Many BIOS's identify the boot frive to grub as (hd0), regardless of thich drive it is.
Its therefore possible for your drives to be reordered for the kernel but not the BIOS.
This would produce your symptoms. Its easy to check.

At the grub splash screen, press e
find the root (hd0,1) line, make ot read

BradN · Posted: Thu Feb 28, 2008 6:25 am Post subject:

NeddySeagoon, the problem doesn't seem to be with grub, but with the kernel itself not finding the drive anymore. I don't think the device to the kernel would have changed, but perhaps something is messing up and it isn't finding it at all now.

I seem to remember this type of thing happening with some odd jumper settings... the bios would find the drives fine but then linux wouldn't... make sure the jumpers are master/slave and not cs for a cable with two devices and maybe it will help. Also, check the kernel boot messages for what it says about the drives (shift+pageup if you can't see them).

This does seem to be a bit of an odd problem though.

didymos · Posted: Thu Feb 28, 2008 7:42 am Post subject:

BradN · Posted: Thu Feb 28, 2008 7:50 am Post subject:

Ahh, I missed that part of his comment, but still discussing grub is beside the point since grub's identifiers haven't seemed to change (if they had, it wouldn't be able to load the kernel anymore).

Does kernel sata dynamically assign identifiers like that? I've never experimented to find out... I've always had two hard drives plugged into the two ports on my motherboard.

Diezel · Posted: Thu Feb 28, 2008 9:13 am Post subject:

Correct me if I'm wrong, but if grub loads the kernel everything is fine until it's done loading. So the problem should be the part that says

mikegpitt · Advocate Joined: 22 May 2004 Posts: 3224

The other usual suspect is that the filesystem you are using hasn't been compiled into your kernel.

jburns · Posted: Thu Feb 28, 2008 8:24 pm Post subject:

If you are using the SATA/PATA drivers ( /dev/sdxx ) then adding drives can change the device used to access your drives. What does it display when it can't find the root partition?

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

I had to change my SDA to SDD in the grub.conf and fstab files. Thanks for all the help!