Preventing respawns for non-operational HVC terminals

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest

If you enable user logins on a terminal that is not available or not operational, systemd keeps respawning the getty service.

About this task

If user logins are enabled on unavailable HVC terminals hvc1 to hvc7, systemd might keep respawning the getty program. To be free to change the conditions that affect the availability of these terminals, use the ttyrun service to enable user logins for them. HVC terminals are operational only in a z/VM® environment, and they depend on the hvc_iucv= kernel parameter.

Any other unavailable terminals with enabled user login, including hvc0, do not cause problems with systemd.

Procedure

Perform these steps to use a ttyrun service for enabling user logins on a terminal:

Enable the ttyrun service by issuing a command of this form:
```
# systemctl enable ttyrun-getty@hvc<n>.service
```
where hvc<n> specifies one of the terminals hvc1 to hvc7.
Optional: Start the new service by issuing a command of this form:
```
# systemctl start ttyrun-getty@hvc<n>.service
```

Results

At the next system start, systemd starts the ttyrun service for hvc<n>. The ttyrun service starts a getty only if this terminal is available.

Example

For hvc1, issue:

# systemctl enable ttyrun-getty@hvc1.service
# systemctl start ttyrun-getty@hvc1.service