== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 03:55:10 (1788854110)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11384     1259920   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16212     1255092   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30828     3575940   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12772     3594136   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170076   1% /mnt/lustre