Increase number of loop filesystems

From SolusVM

By default Linux allows you to mount up to 8 iso files simultaneously. For some XEN VPS nodes this is not enough.

The solution

nano /etc/modprobe.conf

And add

options loop max_loop=128

When you want to mount up to mount up to 128 drives simultaneously, or change 20 into 15 when you only need 15 mounted iso files.

Once this has been done you will need to reboot your server for it to take effect.