[linux-lvm] Removing a very old physical drive - revisited

[malahal at us.ibm.com]

Nicholas Robinson [npr at bottlehall.co.uk] wrote:
> Hi Malahal
> 
> In the absence of fixing the underlying problem, I've renamed the
> volgroup and removed the 30GB disc that was the original aim of the
> exercise! I thought I was getting somewhere, but now the server won't
> boot by itself, I have to use a rescue disc and then chroot and start
> the critical services manually. It is something to do with the change in
> device name from /dev/sda to /dev/sdc, but I can't see why. It gets to
> the point where it should be trying to mount the volgroup and then hangs
> without any diagnostic. Everything looks okay in /etc/fstab.
> 
> I am confused about grub.conf as the (hd0,0) is wrong, given that
> device.map lists /dev/sdc as hd1, but swapping grub.conf to specify
> hd1,0 to match device.map fails with invalid disc or similar and using
> map (...) statements to swap them over or changing device.map don't work
> either.

(hd0,0) is the first partition on the first disk found by your BIOS. It
maybe slightly different from how the OS sees the disks. Device.map is
generated by BIOS but it never uses it as far as I know. You can run
'grub' from shell and find out which disk has the 'boot' code.

> I always used to think the biggest advantage of linux over windows was
> that when it failed it told you why. It hasn't been too helpful in
> recent days.

The software tries to tell you why it failed if it failed. You seem to
be getting into a hang here and it is harder for the software to tell
you what went wrong. You have the option of changing the source code and
instrumenting in Linux if you know what to do. :-(

> I think I will copy everything off the disc tomorrow, reinstall fedora
> 11 on it from scratch (having removed the usb drive!!!) and then
> restore. Life's too short.

I agree.