== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:05:13 (1789279513)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       17452     1253852   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9712     1261592   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29092     3577844   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14460     3592112   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7169956   1% /mnt/lustre