== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:00:22 (1785949222)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17484     1253820   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9932     1261372   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25876     3581144   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17724     3589296   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170440   1%  /mnt/lustre