Oops...I broke fstab on Centos 5.3

[jedispy]

I was dabbling with some CIS 6.1.1 guidelines and I misread the part about adding "nodev" to the "/dev/VolGroup00/LogVol00 / ext3 defaults 1 1" line. I accidentally entered it as

nodev,/dev/VolGroup00/LogVol00 / ext3 defaults 1 1

After a reboot my system won't mount. It trips during bootup at the line that reads

fsck.ext3: No such file of directory while trying to open nodev,/dev/VolGroup00/LogVol00
nodev,/dev/VolGroup00/LogVol00:
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 no swap or
ufs or something else), then the superblock is corrupt, and you might try running
e2fsck with an alternate superblock:
   e2fsck -b 8193 <device>

Here's what I've tried

1. When this error comes up it dumps me out to emergency mode, which is of course read-only. I can't really do anything useful here from what I can tell. I certainly can't edit fstab, which is the source of the error
2. I tried going into rescue mode with my centos installation media, but the rescue operation can't properly mount the volume (I assume since fstab is borkificated).
3. Single user mode fails for the same reason a straight boot up fails.
4. Interrupting GRUB loader by entering cmd prompt and manually running "mount -t ext3 /dev/VolGroup00/LogVol00".

So far none of these have worked at all. Is there any way for me to edit fstab and allow for a successful mount of /dev?

Thankfully this is just a test machine, and not used in production at all.

[Kieren]

I would try a live CD to mount the drive and fix fstab

[jedispy]

I haven't used liveCD much, so a little clarification is needed. How could I edit the /etc/fstab on my filesystem via liveCD? Won't it only show the relative fstab for the liveCD mount?

[Kieren]

If you boot up the live CD you then need to mount your hard drive. If you mount it to /mnt for instance:

mount -t ext3 /dev/VolGroup00/LogVol00 /mnt

You can then edit your fstab as it will be located in /mnt/etc/fstab

[jedispy]

When I attempt that i get

mount: /dev/VolGroup00/LogVol00 already mounted or /mnt busy

Strangely I can't seem to use "unmount" here. Is there an alternative to unmount in Centos?

[Kieren]

Is that using a Live CD? Maybe try mounting somewhere else?

[boardjnky4]

When I attempt that i get

mount: /dev/VolGroup00/LogVol00 already mounted or /mnt busy

Strangely I can't seem to use "unmount" here. Is there an alternative to unmount in Centos?

That means the disk is already mounted, so you should be able to access it. Probably just a matter of finding where it's mounted to.

I would check under /mnt

Are you using a Graphical LiveCD, or are you on the command line only? Usually on a graphical live cd, if you open up the File Browser, you can see the mounted filesystems.

edit: use `man umount` for unmounting a filesystem

[Kieren]

You can find out what is mounted where by using the mount command without any flags:

mount

[boardjnky4]

good call, forgot about that