The virtual disk back end is the location where data of a virtual disk are stored. The back end can be a disk, a disk slice, a file, or a volume, such as ZFS, Solaris Volume Manager, or VxVM. A back end appears in a guest domain either as a full disk or as single-slice disk, depending on whether the slice option is set when the back end is exported from the service domain. By default, a virtual disk back end is exported non-exclusively as a readable-writable full disk.