no serial console after reboot in do-release-upgrade (14.04)

[Leroy Tennison]

Hardware: headless device (Axiomtek NA-330)
Connected to console port (RJ45) via minicom using 115200 8N1
In Ubuntu 14.04 LTS run do-release-upgrade (to Ubuntu 16.04.1 LTS)
At end, confirm reboot
No serial console after that (fortunately the network connection came up allowing ssh access)
Debugging/work-around:
   /etc/default/grub contained GRUB_TERMINAL=serial and
     GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1"
     which was reflected in /boot/grub/grub.cfg
   dmesg | grep tty produced
      [ 0.000000] console [tty0] enabled
      [ 1.612175] 00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
      [ 1.632768] 00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
   systemctl enable console-getty.service
   systemctl enable <email address hidden>
   systemctl start console-getty.service
   systemctl start <email address hidden>
   Ctrl-A F in minicom returned the login prompt which hadn't worked previously

After the work-around the console port turned out to be ttyS0 so some of the above may not be necessary.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1611921/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Leroy Tennison (ltennison)]

Updating package

[Leroy Tennison (ltennison)]

Clarifying "Connected to console port (RJ45) via minicom using 115200 8N1" since it may be confusing. The connection to the device's console port (an RJ45 physical connector) was via a USB-to-serial converter cable connected to a serial-to-RJ45 cable provided by Axiomtek. The connecting laptop used minicom with serial port /dev/ttyUSB0 with 115200 8N1 for communication parameters. This connection worked before reboot (it was used to launch do-release-upgrade).

[Leroy Tennison (ltennison)]

This has now happened on a "headed" server as well - A SuperMicro X9 system.

[Leroy Tennison (ltennison)]

In the latter case
systemctl enable console-getty.service
systemctl start console-getty.service

[Leroy Tennison (ltennison)]

(Well, didn't intend to post but) the above solved the problem.