== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 14:16:09 (1780337769)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11440     1259864   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16132     1255172   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       32212     3574808   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       11332     3595688   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43544     7170496   1%  /mnt/lustre