== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:28:21 (1787480901)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17152     1254152   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9624     1261680   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25872     3580924   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17732     3589148   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170072   1%  /mnt/lustre