== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 22:59:11 (1785466751)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17464     1253840   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10152     1261152   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       31892     3575128   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11708     3595312   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170440   1%  /mnt/lustre