Storage

Tape storage: The smart person's guide

Many people think of computer tape storage as something that's old hat. However, tape has a lot of life left in it, even for progressive businesses.

Image: iStock/lucato

Magnetic tape storage is just about the oldest computer media still in mainstream use. "Rumors of its death have been greatly exaggerated," Twain might write, were he alive today and working as a technology journalist.

Tape storage is an old technology with a bright future, at least according to its supporters. This is a guide to the basics about tape storage.

SEE: The Evolution of Enterprise Storage (ZDNet/TechRepublic special feature)

Executive summary

  • What is it? Storing data on magnetic tapes is the IT industry equivalent of Old Faithful. But unlike the geyser, tape storage is learning new tricks to keep it very relevant for integrating with modern systems. The latest generation of tape media has intelligence and capacities that have never been seen.
  • Why does it matter? It's difficult to find a medium-to-large organization in existence today that doesn't have tape backup in place. Many companies are experimenting by replacing tape with low-end disk systems or cloud opportunities, but those are still just hopefuls against tape's established throne.
  • Who does this affect? Tape impacts everyone in an organization, not unlike storage-area networks, network-attached storage, and backup software.
  • When is this happening? Since the 1950s! The real question is, for how long will it keep happening?
  • How do I get it? Lower-end products are almost a commodity item, whereas high-end products are expensive and can be customized to your business needs.

What is tape storage?

There are four parts to a tape storage system: media/drives and libraries/software.

Magnetic tape media has the same basic parts anywhere you find it, whether it's storing enterprise backup data or serving as a consumer-grade cassette for 1980s power ballads. Tape is wound on a reel, heads perform physical reads/writes, motors advance/rewind as necessary, and it's all packed inside a plastic or metal enclosure weighing a few ounces or pounds. What you'll find in modern storage tapes, and especially in enterprise-grade versions, are stronger materials for reliability, electronic circuits that add intelligence, and grip points for robotic arms.

The most common tape format is industry-standard Linear Tape-Open (LTO), which is currently rolling out in its seventh generation. Many companies make LTO 6/7 media. IBM (with Sony) and Oracle are known for proprietary formats that offer greater capacity at a greater price.

Libraries are the large enclosures that hold active and at-the-ready tapes. These can be as small as a few rack slots or nearly as large as a whole data center, spanning a terabyte to multiple exabytes. Modern libraries are home to robotic high-speed butlers that retrieve, load, organize, and maintain (or even dispose of) the tape media as deemed necessary by applications and management software. Notable library sellers include Dell (soon to include non-tape storage giant EMC), HP Enterprise, Fujitsu, Oracle, Overland Storage, Quantum, Spectra Logic, and Tandberg Data.

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Why does tape storage matter?

Advocates of cloud and commodity disk backup may disagree, but tape has been and may well continue to be the cheapest, most reliable, and simplest long-term (also known as "cold") data storage method. Drives for older tape formats are relatively easy to obtain, and drives for newer formats tend to also read/write media from a generation or two in the past. Unlike most other modern mass storage methods, you can easily move tapes to secure off-site locations and literally store them on a shelf.

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Who does this affect?

When a user or department inside a large organization needs to recall a recently lost or corrupted file, then perhaps a low-level system administrator may find the necessary data in local storage, but what about in the serious cases? If entire databases or servers need restoration — for example, if there's been a hack that needed cleaning or a litigation discovery request to fulfill — then the assignment often is directed to a senior storage manager. Chances are, she'll look to her tape robot to get the job done.

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When is this happening?

Magnetic tape for data storage traces it routes to Univac mainframes of the early 1950s — this happened in 1951, according to Wikipedia, so 2016 is computer tape's 65th anniversary! It's long from retiring.

Tape storage continues to follow a version of Moore's Law. Capacity-vs.-cost continues to improve at a fairly steady rate, keeping slow disk storage at bay and existing without the security risks of cloud systems.

The disconnect between LTO generations and IBM/Oracle high-end drives will probably continue for at least another decade. Virtual tape and the LTO organization's Linear Tape File System are two of the hottest trends, enabling administrators to make many drives act as one and to present libraries as network drives, respectively.

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How do I get it?

That depends on which part of a tape system you need. Media can be purchased in bulk from your favorite local reseller or even from Amazon. Drives and libraries are typically purchased from the manufacturer or from your storage systems vendor. The same goes for management software, although your application decisions will have an impact on what you need and where you should acquire it.

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About

Evan Koblentz began covering enterprise IT during the dot-com boom times of the late 1990s. He recently published a book, "Abacus to smartphone: The evolution of mobile and portable computers".

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