== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 00:54:17 (1788497657)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       17576     1253728   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10052     1261252   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26984     3580036   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16624     3590396   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170432   1% /mnt/lustre