== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 19:05:47 (1786662347)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       17256     1254048   2%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116        9672     1261632   1%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25760     3581232   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17840     3589152   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43600     7170384   1%  /mnt/lustre