== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 23:50:35 (1784173835)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       15900     1255404   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       19000     1252304   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       22408     3584612   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       22168     3584852   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       44576     7169464   1%  /mnt/lustre