/dev/sda1 UUID lost and found again

[karg]

Hello, I'm using Ubuntu 9.10. It happened 2 times so that my /dev/sda1 lost its UUID for some reason or another. This led to the problem that the Ubuntu no longer booted but only said these things:

"Waiting for root filesystem.."

and then complained that the disk specified by ROOT=UUID=.... was not found and then it just failed to shell.

Sounds familiar to anyone?

The first time I spent too many hours to figure out the problem with Google -> got angry and reinstalled the Ubuntu. Luckily it was only the day 2 for the current 9.10 installation.

The second time I tried to cool down at first and then did this after thinking a bit:

1. I changed Grub startup parameters in Grub menu for the latest kernel a bit:
- removed the line that starts with "search"
- changed ROOT=UUID=.... to ROOT=/dev/sda1

* after those changes I could boot up the Ubuntu again!

2. update-grub2 -> grub.cfg was now also setting "ROOT=/dev/sda1" because it didn't find the UUID value.

3. I still wasn't happy with that although now the Ubuntu was booting again just fine. The disk manager said that /dev/sda1 is of "unknown" type. I still managed to get its UUID with "dumpe2fs" and also /etc/fstab was showing the UUID value (in comments) that should be in /dev/sda1.

4. Cheked /dev/disk/by-uuid/ and noticed that the UUID symbolic link for /dev/sda1 was just missing! I don't know why was that, but thought that it might be the problem source.

Guess what... I just created the symlink <UUID> -> ../../sda1 and then update-grub2 and reboot.

Ubuntu was back to normal again! Disk manager also recognized the /dev/sda1 normally.



I hope this helps somebody because I saw a lot of similair writings on internet but no solution for my case...

[vijay_uforum]

thanks

[vikram0460]

thanks..................

[ShawnB391]

This seems like the solution to my problem, however, I don't fully understand the directions. Could you please describe the steps to me in detail? I am a beginner who is experiencing the same problem stated above.

[Köppchen]

I had exactly the same issue, the uuid of the ext4 was lost some reason. I have used your first steps to recover from the problem (using the device, in my case /dev/sda5). Is there a ticket in launchpad already?

[tiroxino]

I report the same problem. For some reason, the uuid of my /home partition was lost and, in order to solve it, I needed to open fstab, comment the line for /home partition and change it to /dev/sda4 instead uuid. Then I reboot and put back the uuid in fstab.
It worked, but now I'd like to know why it happened?!

[Irony]

Grub 2 and uuids are rubbish.

[pierre.fr34]

I had also the same problem. So I changed grub parameters as Karg suggested but in recovery mode. Then I get the opportunity to directly update grub (without booting). After that, it rebooted normally (no need to add symlinks). Really strange !

Anyway, many thanks for your help

(Ubuntu Karmic)