== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 23:37:09 (1789357029)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       16916     1254388   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       20228     1251076   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29872     3577148   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       15736     3591284   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45608     7168432   1%  /mnt/lustre