== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 01:20:11 (1788931211)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11308     1259996   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16148     1255156   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26180     3580840   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17424     3589596   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170436   1% /mnt/lustre