dd_rescue: Problem with Xubuntu (Booting with UUID)

hellmutleo · 08-15-2011, 03:08 AM

Hi list,
this is my first post in this list, and i was not sure which area to choose.

Working with a Lenovo T61 Laptop and gentoo linux for quite a while i used dd_rescue for
backingmup the whole disk. So when necessary (and there were cases ,-( ) i just changed the system disk against my clone and could continue working.

Recently a switched to Xubuntu-10.10 and are quite satisfied. BUT:
When I put the clone disk in the select bay tray and boot for making a backup the system comes up with
/dev/sdb5 on /
/dev/sdb7 on /home
/dev/sda2 on /boot
The partition numers are what they should be but obviously all partitions should be taken from the the hard disk.
AFAICS this is an effect produced by the booting procedure using UUIDs, which are copied by dd_rescue.

Any idea appreciated

Happy Linux'ing

Hellmut

TobiSGD · 08-15-2011, 03:36 AM

Do I understand you right, that sda is your main disk and sdb is your backup disk?
Then it is as simple as that: Zero out the partition table of the second disk, you can do that in the running system. Just do

Code:

dd if=/dev/zero of=/dev/sdb count=1 bs=512

Make sure that the drives are really in that order before you launch this command! It will zero out the partition table of drive sdb!
If you now reboot your system will start completely from sda and you can start the backup.

syg00 · 08-15-2011, 03:41 AM

** deleted post **

Sorry ...

hellmutleo · 08-15-2011, 06:00 PM

Hi TobiSGD,
thanks for your reply ;-)

You are correct: sda is my system disk and sdb is the clone disk.

I understand your solution.
BUT it does not give me the possibility I had when using gentoo linux:
I could just substitute my system disk by the clone disk and
boot the saved state of my system.

I imagine there could be a possibility to change the UUIDs but in that
case I would have to edit the file(s) which controls the boot process.

Any comment on that?

Best regards

Hellmut

TobiSGD · 08-15-2011, 06:07 PM

The procedure I described is only necessary before cloning the disk. After you have cloned the disk it will work the way you want. Detach the original disk, attach the backup disk and your system will work.

hellmutleo · 08-19-2011, 02:46 AM

Hi TobiSGD,
to apply the procedure you describe I need to have access to the clone disk. Using it via USB should not be a problem.
But I do not see how to get that working when the clone disk is in the select bay tray. In this situation my notebook
comes up with a mount list like:
/dev/sdb6 on / ...
/dev/sda2 on /boot ...
/dev/sdb7 on /home ...
and I do not even see which one (/dev/sda or /dev/sdb) is the system disk and which is the clone disk.

Hope that makes my problem somewhat more clear.

Thanks for tackling with my problem

Hellmut