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back to backup basics...

From STORAGE Magazine Vol 6, Issue 9 - December 2006

Selecting the right tape backup media for your organisation and its particular requirements is a major learning curve, if you aren't up to speed with what's available and which solutions might best meet your particular needs. So where do you start? Brian Wall offers some insights

When it comes to identifying the right tape backup media to fit your purposes, what is the best approach for your business? First, of course, you have to be able to distinguish one product from another - not so easy when there are so many proliferating the marketplace, claiming to be the answer to your needs. Then you must decide the best strategy that will deliver the optimum data storage at an affordable price. As if that were not enough, there is also the new raft of legislation relating to data storage, impacting the ways in which tape libraries and peripherals are now being used or may be used in the future.

Yet, according to Chris James, EMEA marketing director at Overland Storage, selecting the right backup media should not have to be a complicated affair. He contends that any organisation should be able to select the solution that best meets its requirements by sticking to a few simple guidelines and working with capable partners. In his view, LTO (Linear Tape Open) has now become the dominant force, winning the war with SDLT (Super Digital Linear Tape) technology to become what he describes as "the de facto industry standard."

There are currently three versions of LTO technology, with version four set for its launch in 2007. James's advice to organisations is to purchase LTO 3, "as it will be around for at least another ten years, though LTO 2 is still sufficient for most current environments. LTO 4, available next year, will run at a faster rate, whilst offering greater capacity, and is considered a good investment for the future," he concedes. "However, at present, networks cannot handle the speeds it will offer."
He is also quick to point out that tape libraries should not be considered in isolation when looking at a solution. "Tape appliances are becoming more widely used as an archive medium, rather than back up and restore. Organisations should be looking to partner with value added resellers [VARs] that can offer expertise in Disc to Disc to Tape (D2D2T) solutions. A three-tiered storage solution of disc and tape is much more effective for primary storage, backup/recovery and archiving requirements. “

It is, of course, vital to buy tape library appliances that are likely be around for many years and compliant with industry standards - otherwise data will not be retrievable when the technology becomes obsolete. "With regards to compliance and regulation issues, LTO 3 technology is, again, a good option as it can support Write Once Read Many (WORM) technology, ensuring that data is non-corruptible once it is produced."

So what is it that a tape format should deliver? Voyager, a privately owned data storage systems and solutions provider headquartered in Marlow, Buckingham- shire, believes it should offer and incorporate all of the following:

• Confidence in the format’s longevity and data integrity
• A clear roadmap for progression
• Possible legacy media support
• Bulk storage or fast access times
• Long shelf life and high duty cycle
• WORM (write once, read many) capability

Voyager is at pains to explain how the technology actually works and it is worth knowing the mechanics as part of the process of making an informed decision (see panel, pg 27). Ultimately, Voyager believes that LTO is the way forward, but each potential user of tape technology must comes to its own conclusions, based on the weight of evidence and its own specific strategy and needs.

TAPE EVOLUTION
It's rare that a business backup hasn't already adopted a certain format, from a tape perspective, says John Greenwood, product sales director, NCE Computer Group (Europe). "However, in the past few years there has been an evolution in the tape industry as legacy formats such as 4mm DDS (DAT - Digital Audio Tape), Digital Linear Tape [DLT] and the 8mm offerings have fallen away.

“The Ultrium variant of the Linear Tape Open format has been adopted by many as the enterprise-class tape format, with its specific strengths being its non-proprietary nature, high capacity, and the competitive element of both the drives and media constantly driving the costs down."

Tape is no longer classed simply as a backup media; the compliance regulations have seen a surge in the philosophy of Write Once, Read Many (WORM) offerings. This is now supported not only by LTO in the current generation, but also by S-AIT and AIT (Advanced Intelligent Tape), and also a firmware release for the SDLT format.

"The 4mm DDS market is far from dead," states Greenwood. "Those who have always backed up their critical data, primarily in single server or SMB environments, continue to use the technology. The drives are sub one thousand pounds and the media - simply because of the volumes produced and, once again, the competition for business in this space - is low cost, too."

Perhaps the biggest threat to this sector is that of the idea of backing up data to a CD, DVD or removable hard drive. “I can think of one very well known organisation that was backing up critical data to multiple removable hard drives, because that's the way it had evolved as a business," confides Greenwood.
Meanwhile, new technologies continue to surface. Both Tandberg Data and Imation have recently unveiled what are, in effect, 'Disk in a Tape Shell' products, taking the benefits of random access technology and its performance, and combining that with the removable storage element of traditional tape. So which of these is right for your business, you may ask?

"I'm sure, if you sat down with a mathematician," says Greenwood, "you'd be able to create a formula that applies to certain profiles of customers - taking into account their capacity and performance need, budget, and technology and brand experience - and with these factors be able to estimate fairly accurately what would be of most interest to them.

Unfortunately, we're not mathematic- ians, but like to feel that, armed with the right information, we've got enough experience to make the right judgements."
Breece Hill chief executive officer Robert J Schaefer also highlights what he considers to be key considerations when purchasing a backup solution, namely:

• Cost of long-term data storage
• Cost of ongoing maintenance
• Data integrity verifiers to ensure accurate data recovery
• Simplicity of data portability for disaster recovery protection
• Integration with backup management software

Equally, he stresses the importance of understanding:

• The retention period for the protected data
• If there is an off-site storage requirement
• Legal requirements governing data protection
• Current data protection policies and processes
• And integration requirements with existing infrastructure

Previous data protection solutions - disc-based and tape-based systems - only address some of these issues, due to the inherent limitations of each technology, he says. "Backing up data to disc provides the fastest way to recover data that's been lost due to user error or software/ hardware corruption. Restoring data from disc enables customers to recover data in minutes, versus the hours it sometimes takes to recover from tape. Disk-based backup also provides the highest level of reliability. And yet disc-based solutions lack portability and data security, and are more costly than tape solutions.

"Tape libraries have been the mainstay for most data protection strategies. Recently, tape has been relegated from mainline storage to backup storage. Even that position is threatened by the exponential growth in data content. Libraries now struggle with the performance required to back up data within a shrinking backup window. Still, tape-only solutions offer portability for offsite storage and cost savings, compared to disc.”

He argues that the best strategy for optimal data storage and affordability is a fully integrated solution that combines both disc and tape. "The emerging D2D2T architecture provides disc-based backup for increased reliability, whilst leveraging tape for cost-effective archival storage. This solution enables fast, multiple 'points-in-time-per-day' restores, while ensuring long-term retention and offsite portability. Current systems on the market strengthen the management capabilities of data migration to further reduce the administrative costs and media expenses. These solutions ensure robust protection schemes and eliminate complexity and IT intervention of typical multi-layered solutions."

Capacity and cost factors
Graham Hunt, EMEA product marketing manager, Quantum, believes that, as the role of tape becomes ever more exclusive to archiving - which tends to be accessed infrequently and primarily for the purposes of restoring individual files - emphasis should be placed on capacity and cost, over performance, when selecting tape backup media. "Failing to follow these principles can mean archiving becomes very expensive," he says. As far as the 'right' product is concerned, he stresses the way in which tape libraries tend to get used every day, as businesses back up and archive their data.

"Tape libraries contain moving parts and so are subject to a certain amount of wear and tear. Therefore reliability and maintenance are important issues. It is worth looking for products that rate highly on reliability, and that can be quickly and easily repaired when the need arises. It is also important to consider flexibility. Demands on data storage can shrink and increase unexpectedly, so the product selected should be scalable. This helps prevent unnecessary expenditure when storage requirements change."

Hunt also highlights the importance of classifying data so that it can be stored in the most economically efficient way. "It can be classified according to frequency of usage, need for security and the duration for which it needs to be retained. In making these distinctions, it becomes possible to avoid using more expensive storage solutions for data that can be pushed off to cheaper storage. Businesses that classify data tend to find they can utilise cheaper tape storage to a much greater extent."
And then there is the matter of legislation - not only what is already here, but what is about to assail us. "Legislation is changing the ways in which tape libraries and peripherals are being used and manufactured," states Hunt. "US legislation, which is likely to be replicated in Europe in the near future, requires businesses to publicly disclose data breaches.

Disclosing an embarrassing breach, of course, does untold damage to a business's reputation, so this new legislation effectively means that businesses cannot afford to lose any data. This is driving a demand for tape drives with embedded encryption. Tape is unique, as it can easily be taken offsite and so is at greater risk of theft. This makes encryption of great importance, if businesses intend to continue to use tape as a storage medium."

In order to narrow down the list of potential tape solutions, it is also necessary to evaluate the amount of data within your organisation and its complete IT environment. Therefore, advises Frank Sander, product marketing manager, Tandberg EMEA,”one will need to take into account the amount of data, the available backup windows, backup devices used before, connectivity and performance of the existing servers, and the number of clients.”

After defining the current status, the more difficult task will be to estimate the needs for the future. “To achieve a reasonable return on investment, one will have to make sure the new tape solution will meet expectations today and tomorrow.”

Having done this homework, the list of potential solutions should be much shorter already. “From our experience, we would believe there are only one or two tape formats left and, for each of these, only a few vendors and products,” adds Sander. “In most cases, the technology of choice is LTO, due to its performance, capacity and compatibility.

"Another consideration is that a tape automation product fits the needs of a company much more than a single tape drive. This, of course, is due to the current volumes of data today and also the advantages you will face in the future, with regards to maintenance and reducing the errors caused by the 'human factor'. Finally, it comes down to slot-counting to define the right size, making sure the device is scalable by either adding another generation of tapes and drives, or by increasing the number of available slots."

When it comes to compliance and legislation issues, Sander believes there is a great deal of hype to contend with, meaning very few people are really aware of all the facts. Generally speaking, there are certain documents that have to be archived longer than others.

”Some of these have to be stored in a 'not-amendable' and 'not-erasable' format, so that what in the past has been achieved with optical storage media can now be provided by the WORM-based products. “

This would also provide a thirty-year archival life, enough for any compliance requirements - at least for now. ST