== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 21:41:06 (1787708466)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11280     1260024   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16096     1255208   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       27804     3579216   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       15752     3591268   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43556     7170484   1%  /mnt/lustre