== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 03:25:41 (1769761541)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       22312     1248992   2%  /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       19852     1251452   2%  /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       26728     3580292   1%  /mnt/lustre[OST:0]
lustre-OST0001_UUID      3833116       18560     3588460   1%  /mnt/lustre[OST:1]

filesystem_summary:      7666232       45288     7168752   1%  /mnt/lustre