== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 19:18:51 (1778627931)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19484     1251820   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9980     1261324   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29100     3577892   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14504     3592404   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170296   1%  /mnt/lustre