@steve_v
You are true hero, you have nailed it.
I did as you suggested and placed that script /etc/NetworkManager/dispatcher.d/01-ifupdown to the right place and rebooted. And sure enough: BINGO.
Thank you for that precious hint.

@ralph.ronnquist
I did the tests on a spare machine, doing a fresh-install with the excalibur-netinstall-iso and running the the devuan installer's first option: install
Test 1:  Excalibur - Cinnamon - OpenRC
Test 2:  Excalibur - Cinnamon - sysvinit
In both cases I just edited the hosts file, the fstab, created the mountpoints and rebooted. In both cases NFS was not mounted.

Copying the famous file /etc/NetworkManager/dispatcher.d/01-ifupdown from my local server (daedalus)  to the test machine did the trick..
BTW: Editing the /etc/rc.local file didn't change a thing.

Would you like me to write a simple procedure (a text file) how to fix that problem? Then, where could I send it for inclusion to the release readme file?

Unfortunately I'm not able to fix the networkmanager package.

Once again, to all of you: Thank you for your help.
Sincerely, Andre (andre4freedom)

@steve_v : Thank you.
I have tried my luck to upload some files. You can find them here (hopefully):

(dmesg):
https://pastebin.com/V3iQa77z

(fstab):
https://pastebin.com/HiGjWMAj

(hosts):
https://pastebin.com/hX8evCQY

(syslog):
https://pastebin.com/UvuWqyVw

(boot-log):
https://pastebin.com/s6tumGik

Thank you for volunteering into that mystery.
Sincerely, Andre4Freedom

Thank you for your reaction, Ralph.
Of course, I have searched the files (dmesg and syslog) for these problems and found not a hint.
I could never get that autofs-thing to work, only a tiny part of it. Sometimes.... So I postpone my research.
I have temporarily switched to Linux Mint. There /etc/fstab still works correctly.
BTW: Daedalus did not show the problem, only excalibur.
I will pick up the task again, later.

I tried with these help-files:
https://thelinuxcode.com/mount-filesyst … ng-autofs/
https://cloudspinx.com/how-to-automatic … th-autofs/

To all the developers, supporters, testers and community: Congratulations and Thank You.
The Devuan-Team is the greatest community I know in the computer-world.
André

To Peter:
I congratulate you to your initiative.
We have the same phenomenon here in Europe: Banking and most other activities on the Internet using a WEB browser have become worse than painful. Of course, animated functionalities and scripts are to blame. WEB applications are bloated and clumsy to use, and by the extend of it even sometimes dangerous.
I wish you and your communities luck with that petition.

Just a side-note:
I have just yet installed a fresh Devuan (Excalibur RC1, OpenRC, LightDM, Cinnamon) for testing and can confirm your findings, rolfie:
LightDM lets you login as root.
Some Daedalus- and all LinuxMint don't allow this. You only have login-boxes for users (from the users-range UIDs).
Excalibur shows a login asking the username, then the password. As did Gnome and XFCE with their DMs in older times.
Again, I can live with that.

I had the problem. Specifically, my VLC showed ugly video-artifacts. Green stripes etc.
I resolved that problem by using handbrake to re-synchronise the video/audio stream.
Just make sure the options
"Align A/V Start"
and
"Passtrhu Common Metadata"
are selected.
The process takes time.
If you use ffmpeg to cut away starting and trailing parts ot the downloaded mp4 files, use handbrake afterwards!
I hope this helps.
Devuan Daedalus, OpenRC, Cinnamon

In which runlevel are you actually?

type your

iscsiadm

command and immediately after :

sudo runlevel

And show us the output.
Is there possibly something wrong with your iSCSI configuration or it's set-up?

Another note: iSCSI is good if you have a physically separate TCP/IP network for iSCSI. That means separate switches and cables!
Mixing it up with a network-protocol network gives severe headaches when there is a lot of network traffic.
The low-level network-params are different for block-protocols and network-protocols.
Using NFS is anyway the better solution, since NFS is a network-protocol. Consider that, please.

Thanks for you info.....
but, now I'm lost. Sounds like mystery to me.
Greetings

Very interesting.
I have Daedalus with Lightdm and Cinnamon, but I'm not able to login as root on the lightdm login-screen.
But, isn't it much more important to disable the ssh-login as root on the machine? These is done so automatically when installing the ssh-server. Check it here: /etc/ssh/sshd_config.
And a last point: have a very secure password for root! Obviously.
So much my 2 cents

So this may be the very occasion to install a fresh system:
Devuan Daedalus and choose OpenRC
or
Devuan Excalibur (if you are keen to try, although it's quite stable already) and choose OpenRC.

The standard installer does an excellent job.
Just know that Excalibur has implemented the "usr-merge" already. This makes a dist-upgrade v5 to v6 a bit tricky. Read the notes and instructions.
Good luck!