== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 12:07:12 (1786118832)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       15952     1255352   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       19380     1251924   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29520     3577416   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       15096     3591644   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44616     7169060   1%  /mnt/lustre