== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 09:39:22 (1786196362)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       21332     1249972   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       15580     1255724   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24624     3582396   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       20816     3586204   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45440     7168600   1%  /mnt/lustre