== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 04:30:46 (1780389046)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       18920     1252384   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       22276     1249028   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26992     3580028   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18604     3588416   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45596     7168444   1%  /mnt/lustre