== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 04:24:46 (1782635086)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       13900     1257404   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       18032     1253272   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       32760     3574260   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11808     3595212   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44568     7169472   1%  /mnt/lustre