== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:36:53 (1781285813)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11376     1259928   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16272     1255032   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25888     3581132   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17664     3589356   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre