== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 14:06:02 (1789063562)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      2210048        7936     2200064   1% /mnt/lustre[MDT:0] 
lustre-OST0000_UUID      3771392       23552     3727360   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3771392       24576     3735552   1% /mnt/lustre[OST:1] 

filesystem_summary:      7542784       48128     7462912   1% /mnt/lustre