Outcome
You will have a documented candidate host and a short list of measurable limits: usable memory, available storage, network connection, power draw, heat, noise, and recovery access. This is a selection worksheet, not a PebbleRack product specification.
Before you start
Complete the goal and inventory guides. Prefer an existing spare computer for a disposable first service. If you plan Ubuntu Server 26.04.1 LTS, verify your CPU architecture and installation media against Canonical's current download page. Canonical lists 1.5 GB memory and 5 GB free disk as installation minimums; those are not a suitable capacity estimate for your application, backups, containers, or VMs.
Steps
- Check minimum feasibility. Confirm the candidate can boot a supported 64-bit Ubuntu Server image, has a readable and writable target disk, enough memory for the operating system plus your chosen service, and a reliable network port. Write down measured installed capacity rather than a catalog maximum.
- Separate system, data, and backup capacity. Estimate operating-system space, application space, expected data growth, logs, and a restore copy. A second partition on the same disk is not a backup against disk failure. Start with disposable data if you cannot yet provide separate backup storage.
- Measure the power path. Read the device's actual power supply label and the ratings of any strip or UPS. For an accurate running estimate, use a suitable power meter under idle and expected load. Do not infer wall draw from a CPU TDP or an adapter's maximum rating. An electrician should handle uncertain household wiring, overloaded circuits, or permanent changes.
- Plan for cooling and sound. Read the exact device manual for required clearances and operating temperature. Leave vents unobstructed, avoid enclosing a computer in a tight cabinet, and check noise where people sleep or work. If the host will go in a rack, measure chassis depth, power plug clearance, cable bend, shelf rating, and airflow direction with the specific parts in hand.
- Decide the recovery path. Can you attach a monitor and keyboard or use a documented remote console if network access breaks? Do you have installation media and a copy of important configuration? A headless system without a recovery path is a poor first host.
- Choose now or defer. If the existing machine can run the first disposable service safely, use it. Buy nothing until a real limit appears. If it cannot, record the exact shortfall and compare candidate equipment using the same task and measurement method.
Check it worked
The worksheet names one candidate host, the target disk, a network connection, a safe power location, a cooling location, and a recovery method. Unknowns are explicit. You can explain why you chose it for the first task without claiming it will run every future AI workload.
If it fails / rollback
If the host overheats, throttles, drops power, or has an unhealthy disk, stop the workload, preserve data, and choose another device. If you have only catalog claims, label the choice provisional until you measure the assembled setup.
Safety and data notes
Do not modify mains wiring or open a power supply. Keep liquid and combustible materials away from equipment. Some installation options erase a whole disk; back up anything important before the next guides.
Sources
- Ubuntu, Server download and current release — 26.04.1 LTS and minimum installation figures; checked 2026-09-29.
- Ubuntu Server, system requirements — scenario-dependent capacity guidance; checked 2026-09-29.
- Ubuntu Server, basic installation — backup and partitioning risk; checked 2026-09-29.
Next guide
Continue to guide 04, “Plan addresses and names.”