D1     dmtbl    dd if=/dev/zero of=/dev/mapper/vol bs=128k
D0     dmtbl    dd if=/dev/zero of=/dev/mapper/vol bs=128k
D1     dmtbl    dd if=/dev/zero of=/dev/mapper/vol bs=128k
D5     dmtbl    dd if=/dev/mapper/vol of=/dev/null bs=128k
D1     dmtbl    dd if=/dev/zero of=/dev/mapper/vol bs=128k
D4     dmtbl    dd if=/dev/mapper/vol of=/dev/null bs=128k
D5     waitmsg  dmsetup resume vol