== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 12:16:38 (1782231398)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11440     1259864   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16108     1255196   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       20664     3586356   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       22888     3584132   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre