Archiving Digital Assets

If budgets grew as fast as data does, archiving digital assets would be much less stressful. Because that’s not the case for the majority of storage users and archivists, time and energy must be spent in researching and choosing the best methods of retaining and securing digital valuables.

Performance

The seventh generation of LTO tape technology is expected to be available toward the end of this calendar year. LTO-7 promises to delivery nearly 2.5 times the capacity (6.0 TB est.) and almost double the performance (300 MB/s est.) of the current LTO-6 tape generation in uncompressed format. With generations 8 through 10 on the LTO Consortium’s public roadmap, LTO tape has become the technology standard for long-term storage across industries.

In order to achieve the aggressive performance benchmarks on its roadmap, the LTO consortium introduced Barium Ferrite (BaFe) media with LTO-6. Prior generations used Metal Particle (MP) tape media which, due to the larger particle size could not produce the capacity, density, and performance gains available with the much smaller particle BaFe media. As a result, LTO with BaFe media is expected to reach capacities of nearly 50 TB per tape, uncompressed, by the release of LTO 10.

Portability

In 2010, the Linear Tape File System (LTFS) was announced for LTO. LTFS allowed tape cartridges to be self-describing in that the tape was partitioned. The large partition contained content and the smaller partition contained data describing the content. By providing metadata about the content on the tape, users could access a tape cartridge in much the same way they would a USB device e.g., thumb drive. This technology breakthrough allowed users to access their data without proprietary applications and formats, thereby improving portability and interoperability.

Security

Data security has been a critical factor for many years. The introduction of LTO-4 in 2007 heralded the arrival of drive-based data encryption. From LTO-4 onward, tape users have been able to securely encrypt their data on tape without suffering degradation in performance or storage capacity. In an age of cyber espionage and destruction or theft of data that’s always on line, putting encrypted data on tape and disconnecting the tape media from the outside world, taking advantage of the air gap, precludes all kinds of data mayhem.

Durability

Given a 30 year useful shelf life, LTO media delivers better long term storage characteristics than other magnetic media types which typically have a useful life of less than 10 years. Combined with media health reporting and data integrity verification checks by tape library systems, LTO tape further ensures that valuable bits stored on tape are readily available and accurately usable when called upon.

Scalability

Data grows more quickly than budgets and the infrastructure needed to house it. Unfortunately, adding infrastructure as data growth demands it can be difficult and costly. Adding storage arrays, cabling and power can be complex. Swapping storage out for higher performing devices is prone to error. However, once a library frame with LTO technology (infrastructure) is in place, users can quickly scale their storage volume by simply adding tape cartridges. Furthermore, they can readily upgrade the storage medium to newer, faster, higher capacity tape drives and media without changing their infrastructure. This characteristic of simple “scalability-in-place” is a unique feature of tape. It provides increasing density per square foot through succeeding generations and is a factor that LTO users have benefited from since its release.

Usability

The internet has allowed for data and information convergence that is predicated on client server connectivity through gigabit Ethernet connections and HTTP protocols like S3. The storage behind the readily accessible front end has become object rather than block or file allowing for a broad, flexible storage pool rather than a strict hierarchical structure. LTO tape conforms to this highly interconnected world. Placing a client server style S3 front end and GigE interface on a robotic tape library matches internet connectivity requirements. Accepting that data in object form and writing to LTO in the open LTFS format meets the broad, flexible storage requirements while eliminating complex, proprietary interfaces. As a result, the world of cloud storage and other internet users can now enjoy easy-to-use, portable, secure, and very deep storage on LTO tape.

Cost (LTO Media)

As with all technologies, benefits come with costs. Fortunately, LTO tape and automated tape library costs are among the most economical in the storage arena. Additionally, LTO tape becomes more economical with each succeeding generation of tape technology. Chart 1 below demonstrates the historical price patterns of LTO media from Spectra Logic since the spring of 2007. Each generation of tape media starts at a point slightly lower than its predecessor and trends down to about $40 per tape. Given the increased capacity of each generation of tape media, it means the starting pricing for each generation of media decreased over time from roughly $.25 per gigabyte with LTO-4 media to about $.06 per gigabyte with LTO-6. It is expected that LTO-7 media, when it becomes available late in CY 2015 will open with a list price in the $.03 to $.04 per gigabyte range based upon historical trends.

Cost (LTO Solution)

Although the cost of media becomes the lion’s share as automated LTO tape systems increase in size, the infrastructure costs should not be ignored since they do add to the total cost of ownership. Assuming the tape system encompasses all the features mentioned above, including the S3 front end, GigE connectivity, object storage characteristics, and LTFS open format, the total solution cost looks favorable over the long term relative to even the most economically efficient cloud storage models like Amazon Glacier.

For instance, a 2.5 PB LTO-6 solution with characteristics discussed here would yield a cost per gigabyte of about $.16 at list price. While this appears high relative to Glacier, it’s a one-time cost. In other words, once you’ve paid for 16 months of cloud storage, not counting access charges, you will have paid for a similar LTO tape system with cloud-like functionality that will last for years beyond the initial 16 month payback period.

For more modest configurations that experience extraordinary growth rates and unlimited retention periods, an LTO solution can be more economical than Glacier over the long run as well. Chart 2 below demonstrates the cost curves for T950 and Glacier (not including access bandwidth and retrieval charges) for a customer starting with 500 TB of data and adding 50 TB per month to the archive.

The curves indicate owners of LTO tape systems can see their opportunity / cost relative to cloud storage become favorable within less than three years.

As tape systems grow in size, the payback period for an LTO system relative to the Glacier alternative shrinks to less than one year. Consequently, if you have a lot of data and plan to retain it for a long time, the economics of LTO tape are striking.

The economics and features previously discussed plus the ability to retain access control, security, and better manage your SLAs means the benefits of LTO tape and tape library systems are formidable for media archiving purposes. In comparison to other storage alternatives LTO tape systems and their attendant benefits should strongly be considered to prevent your data growth from running away from your budget while providing numerous benefits unavailable with other storage and archiving options.

This is the first in a two-part series. Look for Part 2: Archiving Digital Assets to be published in July, 2015