Linux in Production: Maintenance You Can Trust

Know what you operate

Maintain an inventory of services, package sources and configuration files. Record which public ports are intentional and who depends on each service. An accurate inventory makes updates and incident response easier.

Make updates routine

Use trusted distribution repositories and review security announcements relevant to installed packages. Schedule changes with enough time to validate the result. Where automatic updates are appropriate, monitor failures and account for services or kernels that may need restarting.

Monitor the service, not just the machine

A running process does not prove that customers can use a service. Check an HTTP response, a mail delivery path or a DNS query from an appropriate location. Combine those checks with disk usage, logs and resource monitoring so that alerts point to a useful next action.

Test restoration

Back up application data, configuration and the information needed to rebuild the host. Keep a protected copy separate from the live system. Restore into an isolated environment and verify that the application works; successful backup jobs alone do not establish that recovery will succeed.

Keep changes understandable

Document the purpose of a change, how to verify it and how to undo it. Small, reversible changes are easier to assess. After maintenance, test the user-facing path and record anything that remains unresolved.