== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 18:41:22 (1786747282)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11132     1260172   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16212     1255092   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       20828     3586164   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       22776     3584244   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170408   1%  /mnt/lustre