== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 08:16:00 (1789301760)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       19244     1252060   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11752     1259552   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24872     3581728   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18720     3588216   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7169944   1% /mnt/lustre