MD='*'
BLK_DEV='*'
BLK_DEV_DM='*M'
DM_CRYPT='*M'
DM_SNAPSHOT='*M'
DM_THIN_PROVISIONING='*M'
DM_CACHE='*M'
DM_MIRROR='*M'
DM_ZERO='*M'
DM_DELAY='*M'
BLK_DEV_RAM='*M'
MAGIC_SYSRQ='*'