== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 06:45:20 (1784198720)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11328     1259976   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       16196     1255108   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       25888     3581132   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       17660     3589360   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43548     7170492   1%  /mnt/lustre