@lanodan Now that you mentioned rm -rf /tmp/*, systemd I think automatically deletes the /tmp/systemd-private-...-<service>-... and /var/tmp/systemd-private-...-<service>-... folders when the service exits/crashes and makes a new one, if PrivateTmp is enabled (RHEL has it enabled). So your temporary files just get deleted anyway.
nginx crashed? Yeah, your whole cache is now gone. Have fun.