== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 16:59:56 (1786049996)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17260     1254044   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9932     1261372   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       28708     3578200   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14888     3592104   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43596     7170304   1%  /mnt/lustre