File system failure - Repair

[fgielow]

Well.. A few days ago I was installing a program, as any other, and tipped "sudo yum install bla bla bla", but in the end of the installation some error messages appeared, regarding rpm and yum's functionality. I then discovered here in the forum that I should run the command "rpm --rebuilddb", and some other stuff, that I cannot really remember now.

Anyways, after these procedures I would have to reboot the machine, and so I did, but after doing so, I couldn't log anymore ! The system boots on "Repair file system", and I do not know how to solve this issue. "All" my files are apparently there, but the hardware in which my /home was mounted do not seem to be recognized at all. In my /etc/mtab (or something like that, can't really remember the name) file it says that my /home responsible hard disk is currently mounted, its name is md3. But it isn't really mounted. And when I run fsck /dontrememberwhat/md3 it says that it is dangerous to run fsck in a mounted device.


Any ideas of what I should do? It is really important that I do not lose any files at all.


EDIT:

After "playing" a little, I rebooted the machine and managed to log in my user ! All
my files are hopefully here, but there are some errors I cannot understand. For example,
when I try to use yum:
"fernando@baco:~$ yum
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   /lib64/libnss3.so: undefined symbol: PKq1_GetPadMechanism, version NSS_3.4

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.5.1 (r251:54863, Apr  8 2008, 01:19:33) 
[GCC 4.3.0 20080404 (Red Hat 4.3.0-6)]

If you cannot solve this problem yourself, please go to 
the yum faq at:
  http://wiki.linux.duke.edu/YumFaq"

And the firefox keeps crashing when I open some specific pages.


What do I need to do in order to repair my system? I am not with my Fedora CD here, but
I will get it as soon as possible. Can any kind of system repair be made while I am logged?
I'm afraid of logging off, because I may not be able to log in anymore, so I wanted to
repair my system as soon as possible.

Thanks,
Fernando.