Warning: The system shell provides access to low-level diagnostic tools that can cause irreparable damage to the system if not used properly. Use this environment only when directed to do so by support personnel.
From here, you cd to the log dir:
% cd /mroot/etc/log
Find the file you want to move out and use scp to copy it. "log" has packet traces, node logs, etc. mlog has management logs (like secd, mgwd).