UDO: why professional optical storage makes sense in a low-cost disk world.

Let's face it. We are living in a world in which we increasingly have to keep everything we produce, at least everything that could be called professional "information" or "knowledge." Financial transactions, claims information, product designs, e-mail, medical images, audio recordings, survey data, blueprints, pre-press images, photographs, video recordings and legal documents are all examples of "knowledge assets" that organizations need to safeguard for the future.

Why is this? And why now? Part of the answer is because we can. Offices may not be paperless, but the bulk of new knowledge assets (99.97% by some estimates) are in digital form. Combined with a steady decrease in the cost of all storage technologies, we suddenly have the means to store a huge proportion of all the knowledge and information we create.

Major trends in the business and government landscape exacerbate the situation. These trends include increased pressure for regulatory compliance, the growing threat of litigation, and the increased use of long-term knowledge assets to drive better performance. Increased regulatory compliance is the most visible new development, and certainly the most talked about. Look on the website of any storage company and you will find references to regulations such as SEC 17-4a, HIPAA, or the Sarbanes-Oxley act. Litigation is starting to get more attention, as the greater scope (all organizations, large and small, public and private, across industries), and financial risk (often orders of magnitude beyond regulatory fines), become clear. The positive use of archival data is only beginning to grab attention, as more organizations discover ways to extract value from knowledge assets. Some are using them to make better decisions, as is done today with archived scanned images in the medical field or seismic data in the oil industry. Other organizations are reusing knowledge assets to cut design costs or speed development. We see this phenomenon of "not reinventing the wheel" in applications as diverse as engineering design, pre-press projects and even animated films.

These trends will continue to accelerate. Keeping knowledge assets safe but accessible, at a reasonable cost, has thus become one of the major challenges facing IT managers today. The challenge becomes even more difficult as the volume of knowledge assets grows exponentially and as the financial pressures affecting IT organizations continue to mount.

What We Need: The Modern Data Archive

In the past, important works of knowledge were kept in physical vaults and libraries. Today's organizations need the digital equivalent. The key requirements of these modern digital archives include:

* Maximum authenticity and trustworthiness: Whether mandated by regulation, required by the courts or simply because the application itself demands it, archival solutions need to ensure that archived data remains unaltered.

* Long archival retention periods: The amount of time knowledge assets must be retained is already seven to ten years in many industries, and the effect of recent regulations and market trends lengthen that period.

* High capacity and scalability: Rapidly growing archive data volumes demand solutions with high initial capacity, and flexibility to scale over time.

* Timely access to archived data: Knowledge assets are useless if they cannot be accessed when needed.

[FIGURE 1 OMITTED]

* Low long-term Total Cost of Ownership: Cost pressures, especially in the current economic environment, are not going away. Any viable archival solution has to have low acquisition, maintenance and operating costs.

Archival Storage Alternatives

The market for what the Enterprise Storage Group calls reference information (which translates ultimately into archival data) dwarfs that of the overall storage market. At 92%, its growth rate is half again as high. This has not gone unnoticed by storage vendors, resulting in myriad "archival solutions" (see Figure 1).

The storage technologies underlying these solutions include hard disk drive-based systems, magnetic tape and optical storage. Each of these technologies has its strengths and weaknesses, and each, when mapped by expected data longevity, is strongest in only part of the storage spectrum.

In Figure 2, at the far left of the curve, the demands for active data dictate on-line storage solutions with uninterrupted availability, high access speed and high throughput. The overall volume of knowledge assets retained, the frequency of access, and economic realities result in a different set of priorities for data further down the curve. In long-term data retention, raw access time becomes less important and data authenticity and trust-worthiness, timely access to data and low Total Cost of Ownership come to the forefront. It may seem convenient to use a storage single product across the entire data lifecycle, but this is seldom practical since no one technology captures all the required characteristics.

[FIGURE 2 OMITTED]

Hard Disk Drive-Based Systems for Archival Storage

Magnetic hard disk drives were designed to provide high performance, uninterrupted data availability for active data. They have been used successfully in this role for many years. Recently, hard disk drive system manufacturers have promoted their products as a solution for archival storage. This is a major shift from the traditional use of hard drive technology. Despite the addition of special tools and interfaces it remains an awkward fit for long-term archival storage (see Figure 3).

[FIGURE 3 OMITTED]

Hard disk drives, used in combination, certainly provide excellent capacity and performance. They do not, however, address all of the key requirements for a secure, long-term data archive. Hard disk-based systems alone fall short in authentication, data longevity, media flexibility and cost.

Systems using rewritable magnetic disks cannot provide the same level of audit trail verification as true Write Once media and are challenged to meet archival storage regulations that demand stringent data authentication. Magnetic disks are spinning mechanical media subject to failure. This inherent vulnerability must be protected through extra system level redundancy and backup procedures. For data that is accessed very infrequently, these extra precautions are not cost effective. Hard disk drive-based systems also don't accommodate the removal of older data for storage in off-line vaults. This too requires additional hardware, removable media (e.g. optical) and administration. Lastly, high operating costs mean that hard disk drive-based systems are typically replaced within five years, resulting in high storage migration expenditures. The combination of these issues makes using hard disk technology unreliable and very expensive if the requirement is to store records for decades.

Tape for Archival Storage

Tape storage was designed primarily for backup and disaster recovery applications. The ability for tape to stream high volumes of information very quickly (both read and write) and the low cost per GB for media make it well-suited for backing up and restoring large data sets.

Tape storage addresses some of the requirements for archiving, specifically in terms of media capacity and system scalability, and initial acquisition cost. It cannot, however, offer secure data authentication, media longevity and high performance random access. In addition, using tape to store data for decades requires hardware and maintenance considerations that can dramatically increase Total Cost of Ownership for a tape archive (see Figure 4).

Like hard disk drives, magnetic tape is inherently rewritable, making data authentication difficult and forestalling acceptance by key regulatory agencies. Tape also falls short in longevity. It is a fragile contact media that degrades with use and can be easily damaged. It is affected by adverse or variable environmental conditions and exposure to magnetic fields. Tape also requires frequent re-tensioning and periodic refreshing (rewriting) to ensure data remains accessible. Lastly, it provides random access times on the order of minutes, an unacceptably slow performance for many archival applications. All factors considered, tape systems are far from ideal archival storage solutions.

[FIGURE 4 OMITTED]

[FIGURE 5 OMITTED]

The Role of Optical Storage

Optical storage is the only permanent archival storage technology. Disk and tape technologies rely on magnetic recording techniques that are inherently reversible or corruptible. With optical Phase Change technology, a laser "burns" data onto the recording surface, providing virtually unlimited data life.

Optical storage media is impervious to magnetic fields and operates across a wide range of environmental conditions. It does not require expensive, highly redundant architectures to ensure data integrity and needs little or no maintenance. Media removability and backward-compatibility dramatically reduce the need for frequent data migration, helping optical storage achieve an exceptionally low Total Cost of Ownership, as low as one-tenth the cost of competing technology solutions.

UDO (Ultra Density Optical): Permanent Archival Storage

UDO is the first storage technology designed specifically for professional data archive applications. Based on ultra density, blue laser technology, it is the recognized successor to 5.25-inch MO (Magneto Optical) storage and is available in both Rewritable and true Write Once media formats (see Figure 5).

Write Once Technology

The recording surface of Write Once UDO media only permits data to be written a single time. The software or firmware "emulation" of magnetic disk and tape products simply cannot provide the same level of data integrity afforded by true Write Once technology.

Future Roadmap with Backward Compatibility 

30GB UDO, offering more than three times the capacity of 9.1GB MO, at one fifth the cost, is the first generation in a roadmap stretching to 120GB. Future UDO drives will be backward-compatible and adhere to the same ISO standard 5.25-inch form factor, maximizing investment protection in earlier generation media and libraries (see Figure 6).

[FIGURE 6 OMITTED]

UDO provides the critical elements for archival storage environments: permanent optical media for less frequent data migration, Write Once recording to achieve greater trustworthiness, high capacity media for cost-effective storage volume and millisecond seek times to gain quick data access.

Low Total Cost of Ownership

UDO has the lowest TCO of any archival storage solution. With attractively priced 30GB media, the acquisition cost of a UDO library approaches much less reliable tape or DVD solutions and costs a fraction of hard disk-based systems (see Figures 7 and 8).

Combined with its inherent authenticity and trustworthiness over time, outstanding capacity and scalability, and excellent random access attributes, UDO's low TCO makes it the ideal solution for a professional archive strategy.

[FIGURE 7 OMITTED]

[FIGURE 8 OMITTED]

Dave Dupont is vice president, marketing, and Steve Tongish is director of marketing, EMEA division at Plasmon (Englewood, CO)

www.plasmon.com