== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 04:57:11 (1780390631)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19864     1251440   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       22448     1248856   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26776     3580244   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18836     3588184   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45612     7168428   1%  /mnt/lustre