LTO Linear Tape-Open
An open tape standard from 1998, created by HP, IBM and Quantum to break the dependence on proprietary tape formats. Still the cheapest and most durable way to store large amounts of data for a long time.
LTO-9 holds 18 TB uncompressed per cartridge. Access is sequential — finding a single file takes seconds to minutes while sequential reading is surprisingly fast, which makes tape unsuitable as storage but excellent as an archive. The advantages are cost per terabyte, longevity (manufacturers state 30 years) and that a cartridge on a shelf draws zero watts. The decisive property today is the air gap: a tape sitting in a cabinet cannot be encrypted by ransomware. LTFS makes a tape look like a filesystem. Backward compatibility is limited — modern generations read only one generation back.