[POSSIBLE BUG] After reboot virtual servers names and information was gone

What version of Virtualmin do you have there? Were these domains restored from backups or were they created originally on this system? (We've seen this happen a handful of times over the years, but I don't know that we've ever been able to reproduce it.)

Those are the IDs of the virtual servers. And, it is pretty likely to be a bug that causes it, but we need to figure out how to reproduce it in order to fix it.

OK, I talked to Jamie about it, and it apparently happens when the files in /etc/webmin/virtual-server/domains are empty or incomplete.

So, start there. What's in those files? (There should be one for each domain on your system.)

You're not that fucked. You can import them into Virtualmin, usually pretty easily using the "Add Server->Import Virtual Server". The actual home data is what's really important, and you presumably still have all of that. The one tricky bit is the passwords that Virtualmin used to know now won't. The more you know about your domains (or the less you changed them from the Server Template settings you created them with), the easier this is.

But, if the domains were heavily customized on an individual basis, it could be tedious to put them back together.

Knowing you were using WHMCS might be useful data. We've never been able to reproduce this problem, but we don't use WHMCS (Eric does, but he only has a few domains on his personal server, I think), so maybe that's where it's coming from. Sorry you've run into this; I know it's not much comfort that it almost never ever ever happens (I've never personally seen it in ~15 years of using Virtualmin on dozens of servers). If we can figure out how to reproduce it, we can fix it for good. So, it happened immediately after a reboot? Were you creating domains immediately before rebooting?

I'm trying to figure out if it's possible there was some sort of data corruption at the file system level due to shutting down while an operation was in progress...we lock files, but I could see there being a possible race condition where we made a temp file but then never got to move it into the final position. I'm not sure where we write temp files for that...maybe just in /tmp/webmin or /var/webmin somewhere...it'd be worth poking around in there, just in case.

Also, make backups! There's several tools in Virtualmin for backing up, and there's a Webmin Config File backup that's super handy; the config files are very small, so you can back them up frequently without it impacting your system performance or disk space in any notable way.

Yes, I also recently experienced this case.

Does anyone explain why this can happen? And please help the solution.

Thank you very much