== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 19:18:51 (1777504731)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17060     1254244   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       20028     1251276   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25008     3582012   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20688     3586332   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45696     7168344   1%  /mnt/lustre