== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 20:51:21 (1787446281)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11388     1259916   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16300     1255004   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       22612     3584380   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20980     3585928   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7170308   1%  /mnt/lustre