Storage tiers are the layered approach to keeping video at different cost-and-speed points as it ages. Fresh footage that might be needed any second sits on fast, expensive storage (hot); older footage moves to cheaper, slower storage (warm, then cold); and the oldest moves to the cheapest, slowest archive. The principle mirrors moving paper files from the desk, to a cabinet, to off-site storage: keep what you use close, push what you rarely touch far away and cheap.
The economics are dramatic. On cloud object storage the span from a hot tier to deep archive can be roughly 20× or more in price per terabyte, so tiering a large archive can cut storage cost substantially — a worked example of 100 TB over 90 days can fall by around two-thirds when older data ages down to colder tiers. Lifecycle (information lifecycle management) policies automate the transitions by age, so footage moves and eventually expires without manual work.
The defining pitfall is the retrieval-cost trap. Cold and archive tiers are cheap to store but charge to retrieve, often with minimum-storage-duration penalties (30, 90, or 180 days) and retrieval latency of minutes to hours — so you must never write continuous live video straight to deep archive, and you must budget for the cost and delay of getting cold footage back when an investigation needs it. Tier by how likely footage is to be needed, not just by age, and remember archiving does not exempt footage from retention limits (GDPR Art. 5(1)(e)). This is engineering guidance, not legal advice.
