== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 12:20:19 (1786206019)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      2210304       12160     2196096   1%  /mnt/lustre[MDT:0] 
lustre-OST0000_UUID      3771392       25600     3743744   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3771392       25600     3743744   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7542784       51200     7487488   1%  /mnt/lustre