Enable persistent storage for the systemd journal log

Overview The assumed default setting in /etc/systemd/journald.conf is Storage=auto which implies that systemd journaling will only persist the journal if the expected storage location is available. Otherwise, the journal data is stored in memory and lost between reboots. /var/log/journal does not exist by default. Create it to keep and query events from previous boots. Considerations: Syslog still provides the persistant log records, so enabling persistant systemd journal logging does cause a level of duplicaiton. There are sane defaults: SystemMaxUse is 10% for peristant storage in /var/log/journal, or 15% for memory use in /run/log/journal SystemMaxFiles=100 SystemMaxFileSize = SystemMaxUse/8 More config options such as MaxLevelStore can help control how fast storage is consumed. Create storage and enable storage location mkdir -p /var/log/journal systemd-tmpfiles --create --prefix /var/log/journal systemctl restart systemd-journald