Blktap creates kernel block devices which realize I/O requests to
processes implementing virtual hard disk images entirely in user
space.
Typical disk images may be implemented as files, in memory, or
stored on other hosts across the network. The image drivers included
with tapdisk can map disk I/O to sparse file images accessed through
Linux DIO/AIO and VHD images with snapshot functionality.
This packages includes the control utilities needed to create
destroy and manipulate devices ('tap-ctl'), the 'tapdisk' driver
program to perform tap devices I/O, and a number of image drivers.