== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 11:18:55 (1788880735)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       20392     1250912   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       13000     1258304   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29880     3577140   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13672     3593348   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre