== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 21:17:33 (1786843053)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       16220     1255084   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       19596     1251708   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       21340     3585680   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       23344     3583676   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44684     7169356   1%  /mnt/lustre