I guess I am really not the first one to ask this, but I didn't find a specific thread for my problem. I have the possibility to make a snapshot of my ISPconfig machine (slave in this case) I would like to try an update from e.g. Debian 10 to 11 or 12 and then ISPconfig 3.2.x to 3.3.x, but in case I get stuck, I want to go back to the snapshot containing the old, running system. A problem with this strategy is, that mails and website-database related actions in the meantime would be lost. So this is my question: can I disable all the services like postfix, dovecot, apache, mysql in the running system BEFORE making the snapshot and keeping them disabled during the update processes until I either succeed or have to pull the snapshot out again? As far as I unterstand, the often mentioned maintenance mode only prevents other users from logging. Thanks for any hint and sorry, I the advanced users are bored or annoyed from this questions...
Sure. But this qiestions i not ISPConfig specific, it applies to any linux server. If your hoster supports that or if you run your server in a virtualization environment like KVM or LXC, then you can take snapshots if your OS.
Thanks for your anser! But: I CAN make snapshots. But my problem is: how can I keep the ISPconfig or better the hosted servers on it "isolated" or "offline" while updating the whole thing... So making the snapshot is easy and possible, but it is of little use, if I overwrote all things that happened since making it when deciding to rollback to the snapshot... Sorry if I didn't get that clear before
If you do not want a service to be reachable, then you can stop it. So if you do not want the new mail to arrive, stop Postfix. Alternatively, close port 25 on the firewall. Besides that, update processes are a fairly standard thing, and it is more than unlikely that you will ever have to roll back a snapshot. So I would not stop any services for a normal ISPConfig or OS update.
Okay, so it is done the "manual" way... stop services, activate firewall and so on. I hoped there is a "main switch" so stop the servers from talking with the outside, sort of "ISPconfig single user mode" ;-) Thanks anyway for the quick answer!
And this is how it worked for me: I finally took your advice regarding firewall rules, setup a new firewall rule in ISPconfig, allowed only ports 22 (for my console) and 443 (I was able to switch all important websites to maintenance mode with my own tools on the site ("Nofall-Seite.php", so I left 443 active so they were visible to customers most of the time during the update process with an info regarding maintenance). The postfix and dovecot ports were not reachable, so nothing could happen. Then made the snapshot of the VM running ISPconfig, made the Debian and ISPconfig updates. When successful I disabled the firewall rule again and removed the maintenance status of the websites.
