== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:27:09 (1789036029)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11536     1259768   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16168     1255136   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       28872     3578008   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14732     3592176   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170184   1% /mnt/lustre