== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 01:58:21 (1781243901)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11316     1259988   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16192     1255112   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29972     3576964   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13624     3592948   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43596     7169912   1%  /mnt/lustre