== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 03:27:43 (1781249263)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11460     1259844   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16372     1254932   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30956     3576064   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12648     3594372   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170436   1%  /mnt/lustre