== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 09:12:06 (1790687526)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       12964     1258340   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       17928     1253376   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25000     3581880   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18608     3588356   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170236   1% /mnt/lustre