1. cd /dev/mapper/
    2. ls -la
    1. dmsetup ls
    2. dmsetup info xxxx
    1. fdisk /dev/vdd
    2. cat /proc/partitions
    3. dmsetup create fake_disk << EOF
    4. 0 128 linear /dev/vdd1 0
    5. 128 1719869120 zero
    6. EOF
    8. blockdev --getsize64 /dev/mapper/fake_disk
    9. mkfs.ext4 /dev/mapper/fake_disk
    10. mount /dev/mapper/fake_disk /mnt