== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:05:36 (1781629536)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       18444     1252860   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11364     1259940   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24760     3582260   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18792     3588228   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43552     7170488   1%  /mnt/lustre