I had some issues with my older setup using OMV 3.x (the last 3 version - 3.19? I don't recall) and have now installed a fresh up-to-date OMV 4.1.23-1.
One issue that I had previously was regarding the FTP service and unfortunately I have the exact same issue again:
I have configured FTP to work implicitly with SSL / TLS on port 990 and everything is working absolutely fine. Until some time later that day (I haven't figured out how long the time span is, a couple of hours at least) the FTP service obviously stops working or runs into some kind of eror state. There is no error given in the FTP log, the service itself runs, users are able to log in but then no folders can be displayed and the connection times out.
If I then log into OMV and restart the FTP service (by setting the FTP to disable, apply and re-enable and apply) everything will be working fine right away. I have already thought about running a service-restart-script every few hours or so since that seems to solve the problem, but I'd love to hear your suggestions.
Especially since I experienced the error on the 3 version and now have the same on an entirely fresh install as well.
Here's the log of FileZilla when trying to connect:
after trying repeatedly it gives me the message I have exceeded my maximum number of connections, so it seems the old connections aren't terminated. Here's the same log the same log scrolled down a little
and here's the log a few minutes later after disabling / re-enabling the FTP service (the same log again, a little further down):
Here's all of the logs of the FTP service of OMV of the same time - saying pretty much nothing in my opinion:
Any help would be greatly appreciated! I just can't figure it out...