== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 23:43:44 (1786419824)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11136     1260168   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       15992     1255312   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25916     3580852   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17668     3589268   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43584     7170120   1%  /mnt/lustre