Choose storage for a continuously running monitor

Check the release’s minimum before shopping

Sunstead’s current Pi 5 DIY image recommends a 16 GB or larger microSD card. Consult the download page for the current image size and supported hardware. The compressed download size is not the installed storage requirement.

Leave room for the operating system, application data and normal growth. Do not assume every byte advertised on the card remains available to history. Partitions, filesystem overhead and installed files also use space.

Separate capacity from performance and endurance

Capacity answers how much can be stored. Performance affects how storage operations behave. Endurance concerns the writing workload the product is designed to tolerate. These are related purchase considerations, but one label does not answer all three.

Raspberry Pi’s own cards are described as A2 application-class microSD media tested for its computers. That is a specific performance and compatibility claim, not a guarantee of unlimited life in every monitoring workload.

Read the exact card manufacturer’s endurance claims and their test conditions. Avoid translating a video-recording rating into a precise number of years for an unrelated application.

Plan recovery before the first write

Label cards with the release and preparation date. Keep the downloaded image and its published checksum information. A loose card marked “solar” is difficult to trust during a failure.

Treat image writing as destructive

Identify the target media by capacity and device details before writing. Disconnect unrelated removable storage if that makes selection clearer. Writing an image replaces the selected drive’s contents; a backup on that same target will not survive.

Let the imaging tool complete its verification. Verification checks the write, not every future operating condition. The current Sunstead alpha still has a separate physical first-boot validation limitation, even when the image file and card write pass their checks.

Watch for storage problems without guessing

Repeated filesystem errors, failed writes or a host that stops retaining expected data deserve investigation. They can involve media, power, software or the way the system was shut down. Preserve the evidence before reformatting anything.

• Card model, capacity and purchase source.
• Image release and verification result.
• Current backup location and what it actually contains.
• Observed free space and any error messages.
• Recovery test date and remaining uncertainties.

Review storage when history growth or software changes alter the workload. Buying a larger card is not a substitute for knowing how to recover the information you care about.