== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:19:18 (1783145958)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       15948     1255356   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       19336     1251968   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       23232     3583788   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21352     3585668   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44584     7169456   1%  /mnt/lustre