Free tools for running servers

The calculators and references I use when planning work with clients, free to use. No sign-up.

The tools

CheckWebsite security check

What the internet can see: certificate and TLS, security headers, out-of-date software, open ports and email records.

CalculatorUptime and SLA calculator

The downtime 99.9% or 99.99% allows, the uptime you actually delivered, and what a whole system adds up to.

CalculatorRTO and RPO calculator

Three questions: how much data a failure would cost you, and how long you would be down.

GuideThe 3-2-1 backup rule

Three copies, two kinds of storage, one off-site, and the immutable copy and tested restores of 3-2-1-1-0.

TemplateServer runbook template

Access, dependencies, deploys, patching, backups and fixes for one server or service, in Word or Markdown.

TemplateDisaster recovery plan template

Roles, recovery order, scenarios including ransomware, a checklist and testing, in Word or Markdown.

ReferenceEnd-of-life tracker

When Ubuntu, Debian, PHP, MySQL, PostgreSQL, Node and more stop getting security fixes, with upgrade guides.

Tell me what you're running.

A 15-minute call. You describe the servers; I tell you whether I can help and what it would cost.