== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 04:55:40 (1788771340)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      2210048        8192     2199808   1% /mnt/lustre[MDT:0] 
lustre-OST0000_UUID      3771392       22528     3736576   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3771392       26624     3725312   1% /mnt/lustre[OST:1] 

filesystem_summary:      7542784       49152     7461888   1% /mnt/lustre