== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 20:38:48 (1781224728)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17488     1253816   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10112     1261192   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24916     3581992   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18684     3588280   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170272   1%  /mnt/lustre