== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 07:53:38 (1785412418)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11192     1260112   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16144     1255160   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       31900     3574980   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11704     3595176   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170156   1%  /mnt/lustre