LinuxQuestions.org - [SOLVED] Backup with dd fails

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Backup with dd fails

Hi,

I have two identical hard disks (just differing by the serial number). One is my live disk, the other my backup disk. I backup by doing "dd if=/dev/sda of=/dev/sdb bs=1M" from a live distro (started from USB thumb drive).

To check whether the backup is workable, I remove the live disk and boot from the backup disk. The distro on it (SuSE10.3) uses the dev/by-id scheme in /etc/fstab, so this fails but I correct the ids on the backup disk to the correct serial number.

Thereafter, it still does not boot, but reports

Code:

fsck.ext3: No such file or directory while trying to open <dev...>

The superblock could not be read or does not describe a correct ext2 filesystem. If the device is valid and it really contains an ext2 filesystem (and not swap or ufs or something else), the the superblock is corrupt, and you might try runnung e2fsck with an alternate superblock

  e2fsck -b 8193 <dev>

error on stat() <dev>: No such file or directory

fsck.ext3 <dev> failed status (0x8). Run manually

for two of the four valid partitions on the drive.

However, none of the suggestions work.

I must note that all four partitions have type linux raid (fd), but I never got around to switch from my dd backup to a full raid solution.

What's wrong and how can I fix it. I seriously doubt that the drive is defective, as it has been used only several times and kept in safe storage otherwise.

Thanks,
Marco

Why not try a proper cloning tool like G4L or Clonezilla rather than plain old dd.

Thanks ongte for the suggestion of these tools. However, after glancing at the home pages of these, I get the impression that under the hood they aren't taking care of the device IDs as well. The backup thus should have the same problems as my dd'ed copy.

Marco

I changed the fstab to use the old /dev/sda-naming for the different partitions and then the backup disk comes up OK. I have no idea, why /dev/disk/by-id does not work. Any enlightenment would be very welcome.

Marco

I have made many clones, and in the beginning I had problems with drive notations as well and used the 'old' /dev/sdx# notation to fix the problem. I have been using clonezilla with succes it works great. The last time i used it it did not have support ext4 yet but that may have changed by now.

here is a thread that I started a while ago that may give some insight with regards to the uuid's for hard drives. The title of the thread does not suggest the underlying problem straight away so bare with it as you read it.

good luck
Ron