== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 18:23:36 (1786573416)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       16552     1254752   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       19828     1251476   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       29524     3577496   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       15676     3591344   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       45200     7168840   1%  /mnt/lustre