Linux Format forums

[jolharg]

Yeah I've been having problems with actually installing the kernel.

It's been compiled without an initrd, (expected) but I can't get GRUB to work.

/boot/grub/menu.lst:

title Dan's New Kernel
root (hd0,0)
kernel /boot/vmlinuz-2.6.16.20 root=/dev/hda1

<EOF>

Anyway, it comes up with:
Unable to mount / on unknown-block(0,0)

My FS is Reiser. My distro is Suse 10. My processor I configured it for is PIII. Thanks.

[Nigel]

Did you compile ReiserFS support into your new kernel ?
_________________
Hope this helps,

Nigel.

[jjmac]

>>
Anyway, it comes up with:
Unable to mount / on unknown-block(0,0)
>>

There wasn't a "Panic" string with that was there.

Sounds like grub is passing the correct cli at least. It would either be the above, or the refrence in the table is missing or the reference in /etc/fstab is incorrect.

If the /etc/fstab file is miss-configured the kernel will fail to remount its' root fs just before it attempts to run "init".

If your using one of the gui configs "xconfig" or "gconfig", they should allow you to explore through a tree view. It gives the chance to spend some time going over the various branches.

You will need the support internal rather than as a module.


jm
_________________
http://counter.li.org
#313537

The FVWM wm -=- www.fvwm.org -=-

Somebody stole my air guitar, It happened just the other day,
But it's ok, 'cause i've got a spare ...

[jolharg]

i think i put reiser in the kernel... as i don't have an initrd it's essential, also hard disk generic needs to be Y dunnit?

Actual phrase:

Kernel panic: unable to mount / on unknown-block(0,0)
Please append a proper root= thingy...

something gives me the feeling i shouldn't have put root=/dev/hda1 or the problem is deeper than that...

[jjmac]

Howdy jolharg

>>
something gives me the feeling i shouldn't have put root=/dev/hda1 or the problem is deeper than that..
>>

If your trying to mount the 1st primary partition on your 1st ide drive as the 'root' partition ... then thats correct.

The panic message is refering to the kernel attempting to re-mount the root partition read/write so it can run /sbin/init, and failing at that point.

Check your /etc/fstab file !!!

When ever i/ve had that, it's just been either one of two possibles:

# a syntax error, ie /devhda1 rather than /dev/hda1
# a missing mount path .

Grub is working fine, as it is finding the kernel and it's being loaded and going through preliminary initialisation. After the kernel reads the partition table to get its' own mappings it will already have the root partition mounted due to grub having passed the 'root=' cli string. But it will need to remount it read/write so that it can invoke 'init' and complete its' init process while being able to log.

Thats were it will attemp to read /etc/fstab !

If there is an error there, or it wasn't able to find a correct mapping due to an error in the partition table ... it will spit that message out and just freeze. It wont fall back on the path provided by the boot-loader.

Another install ?, or a liveCD boot, mount the problematic 'root', ... should fix it.

>>
i think i put reiser in the kernel
>>

, best to make sure. As you mention an 'initrd' there may have been facilities that existed in the previous setup that needed an initrd to load support modules/drivers. It wouldn't be to hard to overlook those on a rebuild

A little time traversing the configuration tree gui, comparing it to whats set in the previous config, is time well spent. If you have a previous config ".config", from the initial install and an initrd was being used, there would likely be a few key items that may be modular and so need to be preloaded, but maybe not. Again, that needs to be checked. If so, they will need to be configured as built ins. If the previous config isn't available, or you haven't got one at all, you will be looking at a full fresh configuration from scratch. That should at least occupy a couple of hours and is best spread out over a few sessions to get it right. Backing up the resulting config to use as a base for further updates is highly recomended. As a "make mrproper" will wipe out all the files prefixed with a "dot", remove it from the backup name first. The kernel defaults will probably be off target as per your own requirments so a good bit of time spent on that stage is necessary.

If the previous kernel is available for boot, you may find a copy of its' config in ...
/proc/config.gz , to use as a base.


jm
_________________
http://counter.li.org
#313537

The FVWM wm -=- www.fvwm.org -=-

Somebody stole my air guitar, It happened just the other day,
But it's ok, 'cause i've got a spare ...

[jolharg]

Success! I put Reiser and Generic Disk as Y and it worked! One thing, though - subfs was not supported, as I was using SUSE. Any ideas where I can get a kernel patch for that?

Thanks
Dan

[jjmac]

http://sourceforge.net/projects/submount/

A bit of a run around trying to find the actual down load though


jm
_________________
http://counter.li.org
#313537

The FVWM wm -=- www.fvwm.org -=-

Somebody stole my air guitar, It happened just the other day,
But it's ok, 'cause i've got a spare ...

[jolharg]

yip that's the one i found by googling subfs.
anyway it doesn't compile, it makes lots of errors. Any ideaswhee to get something similar, like automount (does that only do mount, not umount?)
i also don't know how to set it up, i looked at the man pages but i still haven't a clue. aargh!

[nelz]

HAL/D-BUS/pmount is the best way to handle auto-mounting IMO. It all happens in userspace, so no need for kernel patches. If you use KDE, it should handle it for you (especially with 3.5, 3.4's automounting could be a little quirky). With other desktops, install ivman.
_________________
Unix is user-friendly. It's just very selective about who it's friends are.

[jolharg]

yeh i have 3.4 i think... the one that comes with suse 10.... kk ill try that, but you cant eject it if it's mounted as anything other than subfs at ta moment without right clickin the drive and pressin eject