== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 22:02:25 (1787709745)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17372     1253932   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9500     1261804   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26916     3579964   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16672     3590124   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43588     7170088   1%  /mnt/lustre