Warning Running fsck on a logical volume's partition will destroy the logical volume and render it unusable and unrecoverable.
To run fsck on your root file system you need to:
1) Boot from the Fedora rescue CD (or, if you have a DVD, boot with linux rescue at the first prompt.
2) Unmount the root partition mounted in /mnt/sysroot
3) Run fsck /dev/mapper/VolGroup00/LogVol00 (If I recall correctly. Do a ls /dev/mapper for the actual names.) Note that "VolGrp00" will, by default, contain two logical volumes: The swap device and the root file system.
If the rescue system can't find any logical volumes (or if dm, the "device mapper," can't access them (which may be the case from your error messages)), then you'll either need to read about recovering a damaged logical volume or, more likely, need to reinstall your FC6 -- loosing all your data.
Some tools are available for recovering files from a damaged logical volume, but I've never been successful when I tried to use them.
There are also backup tools available, and, if you have a recent backup, you might try reinstalling (or, better, installing F8) and restoring your home directory from the backup.
Note: FC6 is, I believe, obsolete and no longer supported by the Fedora project.
Last edited by PTrenholme; 12-19-2007 at 04:59 PM.