== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 09:36:53 (1787751413)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       19436     1251868   2% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11524     1259780   1% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       32280     3574684   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11328     3595580   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170264   1% /mnt/lustre