== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 00:23:11 (1763356991)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       23100     1248204   2%  /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       20100     1251204   2%  /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       27088     3579932   1%  /mnt/lustre[OST:0]
lustre-OST0001_UUID      3833116       18488     3588532   1%  /mnt/lustre[OST:1]

filesystem_summary:      7666232       45576     7168464   1%  /mnt/lustre