== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:56:12 (1786964172)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17624     1253680   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10084     1261220   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       23832     3583048   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       19760     3586840   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7169888   1%  /mnt/lustre