== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 23:50:37 (1786938637)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       16724     1254580   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       20488     1250816   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       22164     3584856   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       22404     3584616   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44568     7169472   1%  /mnt/lustre