== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 21:38:02 (1784770682)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116        9676     1261628   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16448     1254856   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       26108     3580520   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17476     3589432   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43584     7169952   1%  /mnt/lustre