== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 16:11:06 (1786047066)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17380     1253924   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9592     1261712   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30096     3576560   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13496     3593384   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7169944   1%  /mnt/lustre