== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 22:38:43 (1786761523)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17480     1253824   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9984     1261320   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25764     3581144   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17828     3588940   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7170084   1%  /mnt/lustre