== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 17:51:08 (1783979468)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11500     1259804   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16188     1255116   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       27040     3579980   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       16512     3590508   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre