== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 22:36:58 (1788403018)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       19468     1251836   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11884     1259420   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29852     3577084   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13748     3593188   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170272   1% /mnt/lustre