dmsetup status 之后应该显示
No devices found
但是实际是：
docker-253:0-67187437-pool: 0 209715200 thin-pool 1174 2288/524288 100388/1638400 - rw discard_passdown queue_if_no_space -
docker-253:0-67187437-16a7736cc61cab5d23da4992ecd837ea5b3c3e10bd307fa5b70065e6f6215f49: 0 20971520 thin 1849472 20971519
docker-253:0-67187437-13d4b162d35755119a479bb8c0fb67c28ce249aa125b42c39457198342b18e40: 0 20971520 thin 525952 20971519
centos-swap: 0 4194304 linear
centos-root: 0 36634624 linear
centos-root: 36634624 40960 linear
centos-root: 36675584 41902080 linear
