Sep 24 23:14:15 CMDC01 systemd-journald[544]: Under memory pressure, flushing caches.
That doesn't look good either. What else is running on the machine? The one VM alone shouldn't cause memory pressure.
Here's a theory: You have over committed memory elsewhere and the reason passing in the...
The post you responded to is 2 years old.
That said, /etc/pve directory isn't a real directory, it is a fuse mount of a database. So you probably should be excluding it from etckeeper. I don't use that software so can't tell you how to do it. Sorry.
It looks like you have repositories configured in both /etc/apt/sources.list and /etc/apt/sources.list.d. Having everything in the sources.list file is the "old way" while files in /etc/apt/sources.list.d is the "new way".
I suggest to temporarily rename /etc/apt/sources.list (the file) to...
Well, it is incorrect to have both regardless of why you did it and now you have a different set of errors. Fix that and post the results of what @Neobin asked for.
The most common reason for the error you are getting is incorrect repositories. There are other reasons though, such trying to...
Proxmox VE can be configured to update automatically (see "apt info unattended-upgrades"). This is a Debian feature and I think there are good reasons for it to not be enabled by default (e.g. you don't know what else the admin has installed, do you want it to reboot automatically or not, etc)...
Only to you, unless you are claiming that it affects an up-to-date version of PVE.
PVE 7 is based on Debian 11, PVE 8 on Debian 12. So they would be affected by that bug unless they were updated since the bug was fixed.