== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 15:54:28 (1784058868)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19424     1251880   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11876     1259428   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       31148     3575788   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12440     3594132   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43588     7169920   1%  /mnt/lustre