You can Repair Linux ext2 or ext3 file system by doing following steps.
File system must be unmounted, you cannot repair it while it is running. Take system down to runlevel one (make sure you run all command as root user):
# init 1
Unmount file system, for example if it is /home (/dev/sda3) file system then type command:
# umount /home
# umount /dev/sda3
Now run fsck on the partition:
# fsck /dev/sda3
However be sure to specify the file system type using -t option. Recenly one of our sys admin run the command on ext3 file system w/o specifying file system. Result was more corruption as fsck by default assumes ext2 file system.
# fsck -t ext3 /dev/sda3
# fsck.ext3 /dev/sda3
fsck will check the file system and ask which problems should be fixed or corrected. If you don't wanna type y every time then you can use pass -y option to fsck.
# fsck -y /dev/sda3
Please not if any files are recovered then they are placed in /home/lost+found directory by
4) Once fsck finished, remount the file system:
# mount /home
5) Go to multiuser mode
# init 3
Hope this would help