== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 16:00:41 (1784059241)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17304     1254000   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9744     1261560   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24680     3582284   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18920     3588016   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170300   1%  /mnt/lustre