Tape Backup in 2013: What's Working and What's Not
You probably have some audio cassettes or VHS tapes lying around in a box somewhere, but you’re not using them, instead accessing entertainment using cloud services (Spotify, Netflix), disk (DVR, DVD) or flash (smartphone) storage.
It’s long been predicted that tape backup would go the same way, but similar predictions were made for mainframes much earlier, and both are with us today. IT evolution is like biological evolution. While dinosaurs are no longer around, lizards and mammals coexist in their own niches.
Tape Backup: What’s Working
Like the rest of IT, tape backup has continued to evolve: the LTO6 tape drives released last year can store 2.5TB of uncompressed data on a single cassette, with random access reads, a far cry from the refrigerator-sized Uniservos that could store 250kB for the UNIVAC I. But it is being replaced for many types of backup.
While disk and flash prices per GB have dropped, tape is still widely used for low-cost, long-term archiving of rarely accessed data. Unlike disk storage, once the data is laid off to tape, there is no ongoing hardware and utility costs, until it is time to restore the data.
Tape libraries are also finding increased application for offline nearline storage of massive data quantities. In addition to major data centers, this includes supercomputing applications such as the National Center for Atmospheric Research‘s Wyoming facility, where the High Performance Storage System (HPSS) opened with two StorageTek SL8500 tape libraries with 26 drives and 20,000 slots holding a 5TB cartridges for a total capacity greater than 100PB.
Tape is also finding uses in the broadcast industry, where multi-GB video files can be offloaded to a tape library and then loaded back to disk when needed for broadcast or editing. To speed access, the beginning of the video can remain on disk, giving time for the rest of the file to be loaded from tape as needed.
What’s Not Working
For small and medium sized businesses, however, tape backup isn’t the best option anymore. Tape backup that’s below the scale of hundreds of terabytes or even petabytes of data doesn’t benefit from the economies of scale that large tape libraries offer. Tape was fine for small and medium organizations a decade ago, give the high cost of disk capacity, but not now when even SSD prices are running under $1/GB and disk storage is pennies per GB.
Yes, a tape cartridge is still cheaper than a disk per GB of raw capacity. But for backup data that is less than <100TB, capacity is not the primary issue.
Tape requires someone to manage the backups, has high backup job failure rates, and is complicated to recover from. Fortune 500 companies can afford to hire backup specialists to make sure everything goes as planned. But for smaller organizations, using a cloud-based backup and restore solution like Zetta Data Protect makes it simple to automate the backup processes and quickly restore files without having to load and search tapes.