== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 07:51:31 (1779882691)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       13264     1258040   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       17916     1253388   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       20552     3586076   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       23024     3583996   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43576     7170072   1%  /mnt/lustre