== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 11:14:46 (1787843686)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19056     1252248   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11716     1259588   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24072     3582808   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       19532     3587376   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170184   1%  /mnt/lustre