httpd/ssh not working after some time

Hi guys, I got a lil problem. I’m running a RPi3 with DietPi. Installed software is Pi-hole, OpenVPN and nextcloud. After some days I can’t access the pi-hole admin console or nextcloud (500 - internal server error). My SSH key isn’t working either and when I try to login with my user/pass I get Access Denied.

The Pi-hole DNS is still working some time but some time later that won’t run either. By removing the power and plugging it back in everything is fixed. Is there anyway to find out what is wrong? Guess the first step will be setting the log mode to Ramlog #2. But where to check and for what to look for?

Actually persistent kernel/boot logs would be fine, which are not included in /var/log by default.

But first you can check for any errors in current session kernel logs: dmesg
Watch out for any red lines, e.g. I/O errors or voltage related or: dmesg | grep random to check for entropy related issues (which other users face lately).

I guess it is nextcloud. Couldn’t find anything helpful in the logs. I have formatted the SD card, did a new dietpi installation + pihole. No problems for days. Installed nextcloud and boom - can’t access nextcloud or pihole.

Since Nextcloud install does not really touch the webserver setup, it must be an indirect cause.

Can you please paste:

dmesg | grep random
journalctl -u lighttpd
journalctl -u php7.3-fpm