== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 01:47:50 (1780811270)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      2210048       14848     2193152   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      2210176       13312     2194816   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3771392       24576     3744768   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3771392       29696     3739648   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7542784       54272     7484416   1%  /mnt/lustre