== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:45:03 (1787121903)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19368     1251936   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       12156     1259148   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       22852     3583776   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20728     3586236   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43580     7170012   1%  /mnt/lustre