== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:51:33 (1789714293)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      2209024        9984     2196992   1% /mnt/lustre[MDT:0] 
lustre-OST0000_UUID      3770368       23552     3744768   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3770368       26624     3741696   1% /mnt/lustre[OST:1] 

filesystem_summary:      7540736       50176     7486464   1% /mnt/lustre