== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 14:52:47 (1782931967)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       21692     1249612   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16140     1255164   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       23740     3583280   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21904     3585116   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45644     7168396   1%  /mnt/lustre