== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 21:47:58 (1786412878)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11696     1259608   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16580     1254724   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30108     3576520   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13468     3593412   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43576     7169932   1%  /mnt/lustre