== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 09:39:54 (1786196394)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       23256     1248048   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       17588     1253716   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24916     3582104   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20656     3586364   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45572     7168468   1%  /mnt/lustre