[mdlug] Mounting problems

[Michael Corral]

2009-10-23, Monsieur Joe Doehler a ecrit:
> I am trying to migrate to my new box that runs Fedora 10. My old box
> runs an older version of RedHat. One hard drive, with two ext3
> partitions, works fine in the old box. When installed in the Fedora
> 10 box, I cannot mount these partitions, either as ext3 or ext2:
>
> # mount -t ext2 /dev/sdb1 /test

Why are you trying to mount an ext3 filesystem as ext2?

> EXT2-fs: sdb1: couldn't mount because of unsupported optional features (4).
> <snip>
> Googling for "unsupported optional features (4)" indicates that I am
> not the only one faced with this annoyance, but resolution escapes
> me, as it does with others.

Hmm, this was one of the first things that came up for me in a search:

http://lkml.org/lkml/2002/11/6/4

The link explains what the problem is, and the solution.
Run fsck on the drive, then mount it. Worst case, mount it read-only:

mount -o ro -t ext3 /dev/sdb1 /test
or
mount -o ro -t ext2 /dev/sdb1 /test

Michael