== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:20:20 (1789035620)
UUID                   1K-blocks        Used   Available Use% Mounted on 
lustre-MDT0000_UUID      1414116       11336     1259968   1% /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16164     1255140   2% /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       27944     3578964   1% /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       15664     3591300   1% /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43608     7170264   1% /mnt/lustre