== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 08:04:56 (1779710696)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11288     1260016   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16184     1255120   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30764     3576116   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12836     3594044   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170160   1%  /mnt/lustre