== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 07:27:28 (1778930848)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       21596     1249708   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16064     1255240   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25812     3581208   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       19824     3587196   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45636     7168404   1%  /mnt/lustre