IPv6 binds on wildcard addresses include binding to the IPv4 addresses.

What does ss -tlnp return? Does the process listen on any ports?

That should only affect ports below 1024.

Your two bind addresses might be in conflict with each other since [::]:5234 includes binding to the first one.

You want https://tabby.tabbyml.com/ instead of tabby.ml

Haven’t used it myself but you could give https://rustdesk.com/ a try.

“How I get a reliable ssh connection” and “What I do with the SSH connection once I have one” are two entirely different things, autossh does the first, my comment was about the second.

OpenSSH also has a built-in tunnel that is more general (-w Parameter) than just port forwarding.

You should be aware that a large number of mail hosters will block all mail from your server merely because it is sent from a dynamic IP address.

If you don’t have a DB or the ability to store data in general none of the open source analytics software will work either.

I was under the impression that there is only one Matrix server implementation. Standards are not really required in that situation.

Regular updates are definitely necessary too. Also, if you do limit SSH users to a chroot make sure you limit TCP (port) forwarding too.

It might be worth mentioning which xmpp implementation you are actually using for your server if you expect anyone to help you. Also in general, more details about your hosting setup, how you installed it, did you follow any tutorial or use any particular installer (e.g. Helm chart on Kubernetes), possibly if you made any changes to the config,…

Borg is also supported by Hetzner Storage Boxes

Oh, all my drives are RAID too, mostly for the convenience of being able to use them while I order a replacement for a failed drive and not having to restore from backup once I get that.

They are anything but small. They are probably one of the biggest German hosting companies out there.

How do you handle the cache invalidation issue with Borg when backing up multiple systems to one repo? For me if I access a Borg repository from multiple computers (and write from each) it has to rebuild the cache each time which can take a long time.

RAID is not backup. Many failure sources from theft over electrical issues to water or fire can affect multiple RAID drives equally, not to mention silent data corruption or accidental deletions.

Ideally you want to backup everything that you didn’t explicitly exclude since otherwise there is always something you forgot.

I have just been using Borg with a Hetzner Storagebox as the target. That has the advantage of being off-site and not using up a lot of space since it deduplicates. It also encrypts the backup. It might take a while for the initial backup at 24TB though depending on your connection.