== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 12:11:50 (1783959110)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       16668     1254636   2%  /mnt/lustre[MDT:0] 
lustre-OST0000_UUID      3833116       21380     3585640   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       21624     3585396   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43004     7171036   1%  /mnt/lustre