== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 00:52:08 (1788843128)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       17476     1253828   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10160     1261144   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       21688     3585332   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21920     3585100   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170432   1% /mnt/lustre