== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 04:16:56 (1781252216)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17960     1253344   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10364     1260940   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29836     3577184   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13716     3593304   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre