A tape drive is a type of storage device that reads and writes data to removable cartridges. These cartridges contain spools of magnetic tape, similar to a VHS tape or audio cassette. Tape drive cartridges have a high data storage capacity but must be written and read sequentially, which makes them best suited for creating full-disk backups for archival and storage.
Even though other types of magnetic tape media are no longer common, tape drives have several advantages that keep them in active use for long-term data backups. First, tape cartridges are less expensive per terabyte than hard disk drives and solid-state drives. Tape drives and cartridges are also less prone to failure than hard disk drives. Tape cartridges are removable, allowing you to keep rolling backups on separate cartridges. Finally, when stored in a stable environment at the right temperature and humidity, tape cartridges can store data for up to 30 years, making them ideal for long-term cold storage.
The most common form factor for tape cartridges is Linear Tape-Open (LTO), which stores data on half-inch magnetic tape. Multiple heads in the drive read and write data in parallel lines running the length of the tape at high speed. The ninth generation of LTO, LTO-9, has a maximum capacity of 18 terabytes uncompressed or 45 terabytes with data compression.