== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:04:51 (1786640691)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11336     1259968   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16188     1255116   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       28776     3578104   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       14772     3591828   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43548     7169932   1%  /mnt/lustre