For people who don't want the hassle and overhead of LVM, Xen supports fast and efficient file-backed block devices using the blktap driver and library.
blktap (blk being the worn-down stub of "block" after being typed hundreds of times) includes a kernel driver and a userspace daemon. The kernel driver directly maps the blocks contained by the backing file, avoiding much of the indirection involved in mounting a file via loopback. It works with many file formats used for virtual block devices, including the basic "raw" image format obtainable by
dd ing a block device.
You can create a file using the
# dd if=/dev/zero of=/opt/xen/anthony.img bs=1M count=1024
Your version of dd might require slightly different syntax—for ...