== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 17:01:19 (1780347679)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       18636     1252668   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11668     1259636   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30072     3576948   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       13480     3593540   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre