How can vterm be set into debug mode?

Login to HMC as hscpe.
Use pesh command to gain root access
Set vterm into debug mode as follows:

1. touch /var/hsc/log/.DEBUG_HSC
2. touch /var/hsc/log/.DEBUG_VTERM
3. reboot the HMC (hmcshutdown -r -t now)
4. Log back into HMC as hscpe, pesh to root.
5. Verify that /var/hsc/log/.DEBUG_HSC and /var/hsc/log/.DEBUG_VTERM
still exist.
6. recreate the problem with virtual terminal.
7. Debug information can be found in /var/hsc/log/vterms.log