SearchEnterpriseLinux: "In the event that something happens to a Xen virtual machine (VM) that prevents you from starting it, it's a good practice to have the virtual machine storage back end mounted in the Linux file system of the Xen-based server. By doing so, you'll be able to repair the VM quickly and painlessly. In this tip, I'll cover how to do this for physical devices that are used as storage back ends."