== sanity test 56db: test 'lfs df -m' only shows MDT devices ========================================================== 02:08:53 (1769065733)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17848     1253456   2%  /mnt/lustre[MDT:0]
lustre-MDT0001_UUID      1414116       25040     1246264   2%  /mnt/lustre[MDT:1]
lustre-OST0000_UUID      3833116       33112     3573908   1%  /mnt/lustre[OST:0]
lustre-OST0001_UUID      3833116       12476     3594544   1%  /mnt/lustre[OST:1]

filesystem_summary:      7666232       45588     7168452   1%  /mnt/lustre