== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 05:54:19 (1787392459)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17780     1253524   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10196     1261108   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29072     3577948   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14480     3592540   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre