== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 00:47:39 (1782622059)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       13164     1258140   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       18132     1253172   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30232     3576788   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13320     3593700   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre