== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 13:33:29 (1787852009)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       19352     1251952   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       11884     1259420   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       30940     3576024   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       12664     3594216   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43604     7170240   1%  /mnt/lustre