== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 00:48:59 (1721882939)
UUID                   1K-blocks        Used   Available Use% Mounted on
lustre-MDT0000_UUID      1414116       17228     1270460   2% /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       23544     1264144   2% /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       27880     3579140   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       23752     3583268   1% /mnt/lustre[OST:1]

filesystem_summary:      7666232       51632     7162408   1% /mnt/lustre