== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 00:18:15 (1743740295)
UUID                   1K-blocks        Used   Available Use% Mounted on
lustre-MDT0000_UUID      1414116       20720     1266968   2% /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       18856     1268832   2% /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       32096     3574924   1% /mnt/lustre[OST:0]
lustre-OST0001_UUID      3833116       12068     3594952   1% /mnt/lustre[OST:1]

filesystem_summary:      7666232       44164     7169876   1% /mnt/lustre