Boot from the installation CD into rescue mode

If you are using Cent OS/Fedora Core/RHEL linux, boot from first CD and at boot prompt type linux rescue nomount:
boot: linux rescue nomount

# e2fsck -y /dev/sda

ref:

• http://www.cyberciti.biz/faq/linux-unix-check-file-system-consistency/
• http://www.cyberciti.biz/faq/can-i-run-fsck-or-e2fsck-when-linux-file-system-is-mounted/
• http://www.redhat.com/docs/manuals/linux/RHL-7.3-Manual/custom-guide/s1-rescuemode-booting-single.html

Tags: CentOS, Fedora, RedHat