== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:29:31 (1777915771)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17468     1253836   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       20588     1250716   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       31124     3575896   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14528     3592492   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45652     7168388   1%  /mnt/lustre