== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 05:37:56 (1788601076)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11180     1260124   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16036     1255268   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       27056     3579908   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16548     3590388   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170296   1% /mnt/lustre