you have essentially exposed your entire home automation system to the internet without encryption or authentication?
Please please please don’t do this, ever. At a minimum use port 8433 but really you should, no must, use a reverse proxy with authentication. See the security section under the installation section of the user guide for how to set up nginx or Apache as a reverse proxy.
But even then, I wouldn’t recommend using a reverse proxy unless you really know what you are doing and know how to monitor and detect when your system is compromised and how to mitigate the damage when, not if, your machine does get hacked. The fact that you opened oh up to the internet with no protections what so ever indicates you probably do not have these skills. So I highly recommend using myopenhab.org with the cloud Connector binding to access your oh when not at home.
For ssh, I hope you are using certificates for logging in and have turned off password only based logins.
Every well known port exposed to the internet is under constant attack. If your system is like mine, I bet you will see in sshd’s log at least one failed attempt to login per minute if not more frequently. You won’t even see the attacks against OH because there are zero pretentions in place.
Here is the tl;dr on why powering off any machine that uses flash storage causes corruption.
Flash writes in blocks.
Each block may contain parts of other files (e.g. config files, OS executables, etc) which also get rewritten when this new write takes place to add the part of this new write you the block. What is really happening is the contexts of that block of storage is being moved to another physical block in the flash storage
When you pull the power while a write is taking place, you not only lose that write but everything that was in that block.
Unless you go out of your way not to, something is always being written to the SD card. So the risk of corruption is really high. And when a corruption occurs, you cannot predict what gets corrupted. It might be a bit of log file or it might be the driver that allows your RPi to connect to your WiFi.
There really is no way out of the box to predict or detect that this corruption occurred or whether it occurred. So if you even suspect it had happened, your only recourse is to rebuild the entire SD card from scratch or from a known good backup).
Another problem can occur after you have been running for quite awhile. SD cards wear out and when that happens corruption also can take place. In that case, you need to rebuild on a brand new SD card.
The fact that your network at worst, sshd at best stopped working strongly implies that a corruption did occur. Of course, since you are running completely unprotected on the internet, someone having attempted and possibly even succeeded in hackng your machine is a possibility as well.
If it were me, I’d potentially save some time and rebuild from scratch on a new SD card and one rebuilt, never expose it to the internet. Or if you must, access it through ssh using certs for authentication (you can set it up to require both a cert and password to get 2-factor auth) or set up a VPN. OpenVPN works nicely on an RPi but there are other easier options as well. Or access your OH UIs through myopenhab.org.
Addendum: in some circumstances you might be able to detect a corruption if you use tripwire or aide to alert when a file unexpectedly changes. However, it won’t be full proof (what if the tripwire database is what gets corrupted?) and you have to be really knowledge to know what does are supposed to change and when I’m order to know if something unexpected happened.
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