== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 02:11:46 (1783145506)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19784     1251520   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       13108     1258196   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25368     3581652   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       19208     3587812   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44576     7169464   1%  /mnt/lustre