HOW TO: Enable Getty in Red Hat EL or CentOS 7

The following example uses ttyj04.

Created a custom file called: "/lib/systemd/system/serial-getty-digi@.service" by copying the serial-getty@.service file:

cp /lib/systemd/system/serial-getty@.service /lib/systemd/system/serial-getty-digi@.service

Set the fixed baud rate (in this example 9600) on the "ExecStart" line and added the –L flag (hard-wired terminal). We commented out the Type line, although we don't know if it is necessary:

# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.

[Unit]
Description=Serial Getty on %I
Documentation=man:agetty(8) man:systemd-getty-generator(8)
Documentation=http://0pointer.de/blog/projects/serial-console.html
BindsTo=dev-%i.device
After=dev-%i.device systemd-user-sessions.service plymouth-quit-wait.service
After=rc-local.service

# If additional gettys are spawned during boot then we should make
# sure that this is synchronized before getty.target, even though
# getty.target didn't actually pull it in.
Before=getty.target
IgnoreOnIsolate=yes

[Service]
ExecStart=-/sbin/agetty -L %I 9600
#Type=idle
Restart=always
RestartSec=0
UtmpIdentifier=%I
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
KillMode=process
IgnoreSIGPIPE=no
SendSIGHUP=yes

[Install]
WantedBy=getty.target

We gave the file executable permissions (not sure if this is required):

# chmod a+x serial-getty-digi@.service

Use systemctl to create the symbolic link and startup the login service via agetty on device: "/dev/ttyj04". Linux systemd will start this automatically during subsequent system boot up:

# systemctl enable serial-getty-digi@ttyj04.service
# systemctl start serial-getty-digi@ttyj04.service

Check the status:

# systemctl status serial-getty-digi@ttyj04.service -l

In our case, we had to reboot the server to get this working reliably, however this may not be neccessary.

To stop the agetty process:

# systemctl stop serial-getty-digi@ttyj04.service

To disable the service and remove the symbolic link:

# systemctl disable serial-getty-digi@ttyj04.service