I am needing to do hard drive maint on my system. It is a raid 5 with 5 drives. I know you have to unmount the file system before you do this. But how do you boot up run it when the file system is unmounted?

The easiest way is to create an empty file named "forcefsck" in the root directory. Just run "touch /forcefsck" as root. Then reboot, and all file systems will be checked except for those flagged as not to be checked in /etc/fstab ("0" in the 6th field).

If you don't want to check everything, an alternative is to boot into "emergency mode," in which the normal root partition is mounted read-only, and therefore checkable, and nothing else is mounted. Instructions for booting in emergency mode can be found at https://access.redhat.com/knowledge/...emergency.html. (That's for RHEL 5, but RHEL 6 is the same in that regard.)