How to check CentOS 6 Server VM Host after a power falure?

The RAID is fine, all UUUU's means all disks in the array are up. I'd not even worry about that for now.

As for the VM's, if you want to run fscks on them, stop the VM's and run

fsck.ext3 (ext4, etc) /path/to/lvm (usually like /dev/vg-name/lv-name)

If you are using KVM, you should be able to use virsh to do anything you need to the VM's. Here is a link to the virsh man page http://linux.die.net/man/1/virsh

If you really want to run disk checks on your raid arrays, you'll have to reboot into single user mode or boot from a live cd so you can fsck the individual /dev/mdX devices. Since the primary filesystem is EXT4, I'd not bother, it's much better than EXT3 with power outages.

Try mdadm --detail /dev/md0 (same for md1 and md2).

Then try the advice given here: http://linas.org/linux/raid.html