== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 05:43:23 (1781689403)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       21140     1250164   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       14992     1256312   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       32688     3574332   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12160     3594860   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44848     7169192   1%  /mnt/lustre