== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 15:26:50 (1782242810)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17292     1254012   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9892     1261412   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       28888     3578048   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14704     3592148   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43592     7170196   1%  /mnt/lustre