"Failed to find an unused loop device"

So after spending an entire day trying to install a domU from a bad ISO I finally had one running which I decided to make clones of. After making 7 additional clones I tried to start them all at the same time but received the error of "Failed to find an unused loop device."

After looking around I found the following site:

http://snippets.aktagon.com/snippets/70-Fix-for-Failed-to-find-an-unused-loop-device-when-using-xen

Here it explains that the Xen machine is not setup to handle this many loop devices by default. By default each domU may take at least two loop devices. The solution to the problem was to create the file '/etc/modprobe.d/local-loop' and place the following line in it:

options loop max_loop=64

After creating this file and restarting the machine I am able to create at least 7 domUs and have them running at the same time.