== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 07:24:06 (1788002646)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       20184     1251120   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       13724     1257580   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       23232     3583788   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21348     3585672   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44580     7169460   1%  /mnt/lustre