== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 07:14:51 (1777029291)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       24772     1246532   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       21760     1249544   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29096     3577924   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16328     3590692   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45424     7168616   1%  /mnt/lustre