== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 17:32:06 (1788211926)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11284     1260020   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16036     1255268   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24992     3582028   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18560     3588460   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1% /mnt/lustre