What to do, and how often.
WEEKLY
Apply security updates Check disk space Check backups ran and files are present Glance at authentication logs for unusual activity Check services are running
MONTHLY
Full system update, with a snapshot taken first Reboot if a kernel update is pending Review resource usage trends Check certificate expiry dates Review log sizes and rotation Check for failed cron jobs
QUARTERLY
Test a restore from backup Review installed packages and remove what is unused Review user accounts and SSH keys, removing anyone who has left Review firewall rules Run a security scan Update documentation
ANNUALLY
Rotate credentials Review whether the distribution is still supported Review whether the specifications still fit Review whether a VPS is still the right choice
THE ONE THAT MATTERS MOST
Applying updates. Most compromises exploit a vulnerability that was patched and not applied.
THE SECOND MOST
Testing a restore. An untested backup is an assumption, and you find out during an emergency.
