grub no find sda4 -- Ok, maybe scsi not in kernel?

jimmy · Guest

Ok, grub's not finding my root. My menu.lst has:

root (hd0,0) <-- single SCSI drive, boot on first partition (1)
kernel /boot/bzImage root=/dev/sda4 <--- part2= swap, part4=/
^
|
\----- there is no part3, just 1,2,4.

And it fails saying it can't find sda4.

We're not even to loading a kernel, so it's not that I may not of compiled scsi support into the kernel, right? (I don't remember if I did or not...)

Let's say I wanted to recompile the kernel from this point -- but I can't even boot the drive -- what do I need? A boot floppy? Can I use the bootable build CD without re-downloading the whole thing? But would the boot floppy be better at finding the drive?

A wee bit confused...

Thanks!

fghellar · Posted: Sat Apr 20, 2002 3:07 am Post subject:

If you can, please boot from the install CD and run

jimmy · Guest

fdisk -l /dev/sda shows:

/dev/sda1 83 Linux
/dev/sda2 82 Linux swap
/dev/sda4 83 Linux

When making filesystems, I used "mke2fs /dev/sda1" and "mke2fs -j /dev/sda4".

jimmy · Guest

Hmm... my cdrom is IDE... nah, this doesn't matter, does it? I should be using "/dev/sda4" to refer to my root in grub, right? (i.e. not in grub-speak of (0,3))

fghellar · Posted: Sat Apr 20, 2002 3:37 am Post subject:

I think you have to check if you compiled scsi support into the kernel too (not as a module).
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jimmy · Guest

Ok, I think it's in there. So, I boot off the CD, get a shell, mount the disk, chroot, and can then start working. I need a boot floppy that does this, huh?

I checked -- it's there. I put some more stuff in and am going to re-compile now, but I expect the same results. Since grub can't read the disk, the kernel can't get loaded. (I think.)

jimmy · Guest

This seems odd to me --

When I boot off the cd, then mount my root drive:

# mount /dev/sda4 /mnt/gentoo

It says something like:
EXT3FS ..... on sd(8,4), internal journal.

I think "sd(8,4)" seems odd -- why "8"? I think it's the first (0) device on the first (0) channel, first LUN (0), etc.

fghellar · Posted: Sat Apr 20, 2002 3:58 am Post subject:

Yes, really odd...
Just to say we're trying everything... change the kernel line in menu.lst to
kernel /boot/bzImage root=/dev/sdh4
and see what happens.
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jimmy · Guest

Ok, tried the sdh4 thang and saw this:

NET4: ....
ds: no socket drivers loaded!
VFS: Can't open root device "sdh4" or 08:74
Please appaend a correct "root=" boot option.
Kernel panic: ...

This is quite similar to what I see with sda4.

fghellar · Posted: Sat Apr 20, 2002 4:44 am Post subject:

If you feel like playing trial and error, try changing it with
sde4 sdc4 sdg4 sdi4 sdb4 sdd4 sdf4
in that order, until one works. Maybe later we can find out what exactly is happening...
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jimmy · Guest

Problem solved, I think.

I recompiled the kernel with more things built in. I didn't really change modules to built-ins -- I just added built-ins.

And after booting again (some may say "rebooting"), and coming up on sda4 (back from the sdh4 adventure) and the new kernel, all looks pretty well.

My original assertions that grub wasn't finding the disk were in fact wrong. Grub had found the disk and was booting my kernel, but my kernel sucked. Now that my kernel has improved, it's booting.

Thank you and cheers.

fghellar · Posted: Sat Apr 20, 2002 4:47 am Post subject:

Wasn't it perhaps that you forgot to include ext3 support in the kernel?

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jimmy · Guest

hehe... perhaps, perhaps...

I need automagical revision control on my "make menuconfig".