magnetic tape has a physical expiry date, and most retention policies don't mention it
not a doom post, just something that came up during an audit last quarter that I genuinely hadn't thought about before. we've been using tape for long-term backup for years. standard practice. our retention policy assumes "tape is stable, data sits there until we need it."
the problem is that this assumption has an expiration date, but nobody knows about it. the shorter answer to why tape deteriorates is: magnetic tape deteriorates because of binder hydrolysis - the chemical process that leads to the breakdown of the compound that keeps the magnetic particles bound together. vinegar syndrome from older tapes produces acetic acid that accelerates deterioration. print-through leads to signal bleeding.
the rough timelines people cite vary by format and storage conditions, but LTO tapes stored well can realistically last 15-30 years. older formats significantly less. the problem is most orgs have no idea how old their oldest tapes actually are or what conditions they've lived in.
I went down a rabbit hole on this after our audit and ended up reading through what Tape Ark publishes on the topic, they do large-scale tape migration work, and the degradation documentation is pretty sobering if your org has archives going back more than a decade.
not saying everyone needs to panic. but "tape is fine, we'll deal with it when we need it" is a riskier assumption than most IT teams realize. the data isn't gone yet for most people. the window is just quietly closing.
has anyone else had to do an emergency tape audit recently?