thexman

@StefanH.
You are very welcome! I did quite a few tests (including switching to mainline but dropped it in favour of the latest legacy). I upgraded the kernel and this also fixed the issue for me permanently without the need of downgrading "systemd". I am currently on ARMBIAN 5.73 stable Ubuntu 16.04.6 LTS 3.4.113-sun8i but I will now upgrade to 5.74 as I saw there is a newer version. You can upgrade your kernel version via "sudo armbian-config" => System => Other. There you can choose the kernel you want to switch to. 4.x.x is mainline kernel and might break specific legacy board features so I would recommend 3.4.113 with version 5.73 or 5.74. But 5.73 already fixed the problem so it is up to you what version you want to choose.
 
Update: strangely the update to 5.74 worked and after that the tool showed me 5.75 which also worked but motd still shows me 5.73. IDK what's is going on here. But I can confirm that 5.73 - 5.75 do work.

@thexman
 
thanks a lot for your downgrade instruction! you saved me hours of trial and error!!!
 
btw: you wrote earlier that you upgraded to the new kernel but then downgraded again. is this still the current situation or did you overcome all issues you had with the next kernel?

@Igor
Can confirm that the updated fixed the issue. Updated to latest kernel, armbian + systemd. Thanks for the fix 👌

Patch is applied and it seems to work, updates pushed up:
https://github.com/armbian/documentation/commit/417821896fedd9623bfc6d7dac13cc5392729c80
https://github.com/armbian/upload/commit/3ea43843df0ccfa7e749b41cffa27f38c3ba53e8

... but it seems not all problems went away. I am experiencing network troubles. 
Lan cable was not connected to the switch 

Ok, thank you.  I'll try.
This is the first such case in my practice. On raspberry this has never happened before.

@Sergio
You don't inevitably need to switch to Stretch to avoid the issue. Simply switching to mainline on Xenial will also work. As already said legacy kernel features will not work anymore but that would be the same for any mainline. Switching can be done through the armbian configuration tool.

@scaevola
Thanks for mentioning me. Here is my script on Github to automatically dowgrade systemd to latest functioning release, just in case that someone is interested or wants to try or use it ;). No need to dig in the original thread. The readme there also describes how to use it. Upgrading to mainline kernel also works, I have tried that the other day. But be aware that some applications especially crafted for legacy might break.

The most practical solution (although not perfect, because it requires reversing the systemd version) was proposed by @thexman in this thread:
https://forum.armbian.com/topic/8852-ssh-doesnt-work-on-orange-pi-zero/?page=3
Just clone his git script, run it and halt systemd updates. This will save your machine from problems with ssh and other services until this would be repaired in ubuntu.

@Igor
It's fine, I thought you were interested in the output of the log. I simply misunderstood your post. It's not necessary to look into or provide support in that case because I also didn't invest much time finding the origin. Furthermore, I'm back on legacy for the moment and stay with it and watch how the systemd updates in the future proceed. Maybe the bug will be fixed and at the moment I have no desperate need to switch to mainline. Thanks for the additional information concerning Armbianmonitor and mainline that is very useful.
 
@scaevola
You are very welcome, thanks for your words I'm happy that the scripts helped you . The issue with systemd is also very annoying for me because my OPi is a DNS server so it really sucks when a core update breaks the whole thing. I'm glad that I have a VNC server on the OPi otherwise it would be a pain in the a** because it works in headless mode (HDMI off)... I find it more convenient to simply execute one single batch file instead of searching every single of the four packages manually. IDK if there is a better way to find and get them without retrieving the download paths directly from Launchpad. A more sophisticated script would consider a specific Ubuntu versions, target platform and parse the download paths automatically. However for the moment this should be ok! Probably there is already a script where you can specify platform, package(s), system version and package version which then retrieves the correct paths and installs the package. Maybe an idea for a future project if not already existent . If your OPi Zeros are not on legacy kernel 3.x, you can check with uname -a, they probably won't be affected at all. If they have kernel version 4.x it should be fine from what I noticed.

@thexman
Thank you very much for recognizing the problem and your github bash files! They are really heplful!
I have Orange Pi PC server at home, which serves as dlna server and also tvheadend and samba store.  So after last update I was really upset when it occurred I can't connect with server anymore through SSH. Fortunately I installed Webmin few months ago and thanks to that I was able to get to webmin virtual console and easy repair the systemd thanks to your files.
 
It just came to me that I've got two Opi Zeros, running as dlna players and they have auto updates on. But yesterday they worked fine. I hope this bug won't happen to them.

Hey BlackWoxs, you are very welcome! I'm very happy that I could contribute something useful that is also helping other people