CentOS to MS Hyper-V Volume Issues

After making an image of a physical linux box (Dell hardware running CentOS), I converted the IMG file to a VDH file and after booting had many issue. One of which was the following error which caused all databases on the respective volume to fail because the volume was in read-only mode.

EXT3-fs error (device hda3) in start_transaction: Journal has aborted

Turns out, the system is telling me that it’s detected a file system/journal mismatch, and it can’t utilize the journal any longer. When this situation pops up, the file system gets mounted read-only. To fix the situation, I had to boot the system (now in the VM environment) in single user mode, dismount the volume and fix it.

I first started by removing the journal from the file system:

# tune2fs -O ^has_journal /dev/hda3

Then I tried to fsck it to correct any possible problems:

# e2fsck -p -f -v /dev/hda3

Unfortunately this lead me to another error: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY. (i.e., without -a or -p options).

Ugh. fsck again….I had originally run it without the -f option and it found no errors, yet it refused to mount in read-write mode. So now running it sans the -p option, -f forcing it to check it anyway, seems to have helped- but this time I needed to be present to hit y to every single error. There were hundreds.

Once that finished I ran it again with the -y option to see if it picked up anything and it was clean!

Time to make a new journal which makes the partition an ext3 file system again:

# tune2fs -j /dev/hda3

I can now mount the partition as an ext3 partition:

# mount -t ext3 /dev/hda3 /mnt/fixed

After rebooting the system seems happy once again with no mounting errors. Quick and simple!