== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 00:01:59 (1788926519)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       17252     1254052   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9832     1261472   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25732     3581288   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17820     3589200   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1% /mnt/lustre