== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:22:13 (1787480533)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11576     1259728   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16376     1254928   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30080     3576856   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13476     3593068   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43556     7169924   1%  /mnt/lustre