== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 15:25:07 (1787858707)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17624     1253680   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9876     1261428   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       20556     3586100   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       23024     3583828   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43580     7169928   1%  /mnt/lustre