== sanity test 56Db: test 'lfs df -m' only shows MDT devices ========================================================== 09:50:29 (1787752229)
UUID                   1K-blocks        Used   Available Use%  Mounted on
lustre-MDT0000_UUID      1414116       11420     1259884   1%  /mnt/lustre[MDT:0] 
lustre-MDT0001_UUID      1414116       15960     1255344   2%  /mnt/lustre[MDT:1] 
lustre-OST0000_UUID      3833116       24756     3582096   1%  /mnt/lustre[OST:0] 
lustre-OST0001_UUID      3833116       18568     3588312   1%  /mnt/lustre[OST:1] 

filesystem_summary:      7666232       43324     7170408   1%  /mnt/lustre