Eleven Free Homelab Tools for the Questions Guides Skip

Every guide I write ends in the same handful of questions. How much hardware do I actually need? What happens when one box dies? Are my backups real or just a feeling? A guide can walk you through a setup, but it can't do arithmetic about your lab — so I built eleven small tools that can, at peira.dev/tools . They're free, none ask who you are, and seven of the eleven keep working once the page has loaded — network unplugged, laptop in a cupboard, whatever. They share one lab profile This is the part that makes them a set rather than eleven unrelated pages. Describe your lab once — tick your services in the sizing calculator, press Save to profile — and the others pick it up. The failure simulator opens with your nodes already modelled; the backup planner knows what data you have; the power-loss playbook knows what's plugged in. Lab doc hands the whole thing back as a Markdown file. Nothing about that profile leaves your browser. No account, no sync, no server that could leak it — which is also why it doesn't follow you between devices. The Markdown export is how you carry it elsewhere. Plan the build Sizing calculator — asks what you want to run and recommends nodes, RAM, and storage. It cares most about RAM, because that's the constraint that actually bites; vCPUs overcommit happily, memory doesn't. Tick "survive one node failure" and it insists on three nodes (a two-node cluster loses quorum the moment one dies). Node failure simulator — kill a node and see which workloads fit on the survivors. It places the critical ones first and names the stranded ones. 3-2-1 backup planner — three copies, two devices, one offsite (the rule CISA recommends ). It's blunt: a snapshot on the same disk as the original is versioning, not a backup. Fix what's broken The overlay network diagnostic is a decision tree born from a miserable afternoon: a container couldn't reach a machine across a Tailscale subnet router, and three layers had to be right — the route in the guest, the ACL