== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 08:20:14 (1789129214)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17644     1253660   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       10248     1261056   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25012     3582008   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18552     3588468   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43564     7170476   1%  /mnt/lustre