While Tape drives are now old and low tech, the cheapest and most reliable media for high volume data backup. Google backs up its data on an average of over 500 Tape Drives per day. Big names in the IT industry like IBM, Sony, Seagate and HP are still developing LTO or Linear Tape-Open devices and technologies. SpectraLogic even built a monster LTO tape library T-Finity in 2011 with 400,000 slots and 3.6 exabyte or 3865470566.4 GB storage capacity!
A Tape drive is essentially a data storage device like Hard Drives, Flash Drives and the more recent Solid State Drives. The difference is that instead of dynamic memory allocation, today magnetic tapes are used to backup large volumes of data for archival purposes. Floppy disks used to have a circular magnetic tape, but pretty much the same principle applies to using tape drives. Magnetic tapes are typically placed in plastic covers referred to as cassettes.
They are used for long-term storage instead of dynamic use since the retrieval and writing of information is through sequential or continuous access rather than random access as in the case of modern storage disks. This reduces the errors caused by improper memory allocation and indexing and gives similar speed for streaming of sequential data (over 140 MB/s or 1120 Mbps) but reduces access speed for random chunks of data as compared to disk drives.
Interfacing is not an issue for the old tech tape drives, since many compatible SCSI, Fibre Channel, SATA, USB and other systems are available. Automation of loading, unloading, storage and retrieval through autoloaders and tape libraries reduces manual handling to nearly zero. Older tape drives designed solely to counter the high prices of disk drives are now obsolete since modern ones use advanced techniques to improve speed, reliability and compression.
While internal buffering and multi-speed access reduce start-stop issues due to continuous access, if the computer used to read/write data on tape drives has lower data speeds than the tape drive it causes shoe-shining or having to rewind or fast forward the tape to a specific point several times.
Nanotechnology has led to lab results of tapes with as high as 35 TB raw storage capacities. While Cloud storage and disk drives are rapidly encroaching on the remaining tape drive markets, its reliability and cost effectiveness are hard to beat.
Magnetic tape data backup is even offered as an option by Cloud Storage companies since they offer more secure backups inaccessible via the internet to hackers, especially indispensable for legal, financial institutions and other sensitive data handlers. Modern tapes are supposed to offer 20 years of error free storage under ideal conditions!
They are more robust than disk drives but recovery from tape backup might be less expedient. Also, backups on magnetic tapes don’t allow dynamic synchronization, forcing entire files to be saved as mostly redundant copies wasting time, effort and space. This has a plus point though – you can’t accidentally write over old data either.
Backups are like medical insurance – you don’t need them unless you REALLY need them! So would you rather have convenient and expensive or cheap yet reliable? A disk backup might be more convenient for a personal user or a small company, but when huge, HUGE backup service providers like Google look for solutions, they want the second choice. With Trillions of GB of data on the line, Tape drives offer unimaginably cheaper storage.