Optical storage remains a top choice for compliance.

The business requirements for a record archive have evolved very rapidly over the last few years. Major financial scandals and recent incidents involving large-scale data loss have turned the spotlight on the management of digital archives. An increased awareness of the value and liability of archive records has resulted in both industry regulation and internal operational risk management.

The requirement for tighter integration of archive policies within an IT infrastructure is creating a demand for more flexible strategies that can accommodate the new regulatory and risk management burden. This need for flexibility is particularly important in the choice of physical storage media since it will, in large part, determine the success of implemented policies. Currently, the two preferred advanced-technology choices for archiving are UDO (Ultra Density Optical) with "True" WORM (Write Once Read Many) storage and disk-based technology such as WORM storage with a CAS (Content Addressable Storage) interface. Each performs the same end function, but the method, cost and effectiveness are not equal. This can be illustrated by examining common archive objectives that are tightly linked to storage media attributes, including record authenticity, record destruction, and TCO (Total Cost of Ownership).

Record Authenticity

For many archived document types it is essential to establish and maintain a very high record authenticity standard as is the case for any record subject to legal scrutiny such as financial statements, medical information and corporate communications (including emails). This is so important that some regulations specifically call for the use of WORM storage technology as one means of establishing a clear audit trail to ensure that records have not been altered.

In recent years, storage vendors have developed specialized magnetic disk-based RAID archive products sometimes referred to as CAS interface solutions. These products have implemented Write Once functionality through a mix of software and/or firmware that emulates Write Once capabilities on rewritable magnetic media.

UDO (Ultra Density Optical) offers "True" Write Once technology implemented at the physical media level. The recording surface of True Write Once UDO media allows files to be written, but the media itself cannot be physically erased or modified. This technology is significantly different than magnetic disk and tape emulation since the Write Once properties of UDO are inherent to the recording surface of the media and are not a function of software or firmware controls.

WORM storage with a CAS interface may be acceptable depending on the authenticity requirements of the organization, but only optical media provides unquestioned physical authenticity and is named explicitly as a preferred archive media by some regulations. Storage media can play a critical role in establishing the admissibility of digital records in a court of law.

Record Destruction

The issue of digital record destruction is emerging as a major consideration for many archives. Exactly how and when data can be destroyed is governed by some regulations and is at the heart of operational risk management. An archive strategy must find a way to balance regulatory requirements to retain records and a corporate desire to destroy them for both practical and liability motives. Here too, the choice of storage media plays a key role.

Some regulations define retention periods that allow data to be deleted after expiration and some go further by actually mandating record destruction and specifying the nature of destruction. Detailed destruction specifications are most common with documents related to security or personal information and typically call for the physical obliteration of the data. In these cases, deleting pointers to files or deleting keys to encrypted files is not sufficient. The records must no longer be physically present on the storage media.

If archiving on a typical RAID system, a simple delete operation does not remove the data from the disk. The only way to physically destroy records is by repeatedly overwriting the targeted sectors with a patterned sequence to ensure no residual trace of the document remains on the media. The US Department of Defense has an often-quoted specification for data shredding on magnetic disk media. The specification (DoD 5220.22-M), which has been implemented in some specialized CAS interface products in the context of a record retention policy, states that depending on the source of the recommendation, targeted sectors should be overwritten between three and 35 times.

By contrast, UDO offers a Compliant Write Once media format designed specifically for data disposition requirements. Compliant Write Once UDO operates like standard WORM media, but has the ability to physically destroy targeted files through the use of a special "shred" operation. This is a one-pass function that provides full verification and unlike the erase pass on magnetic disks, the shred procedure on UDO media leaves no residual traces of previously written files. Compliant Write Once UDO media enables record level retention management with an extremely high standard for physical record destruction.

Authenticity and Destruction Summary

Record authenticity and destruction are just two of many possible storage attributes to be considered when designing an archive. Others include access performance, capacity, media longevity, the upgrade roadmap and Total Cost of Ownership over the life of the data. The priority of these attributes will vary between organizations and among record types within the same archive. Given these diverse demands, it is vital to have an operational understanding of external regulations, internal risk management and the physical storage technology. The rapidly evolving nature of today's record archives demand products and strategies that enable the greatest possible flexibility.

Organizations are compelled to create an archive environment that meets their business objectives, complies with regulations and fits within their own risk management guidelines. This is not an easy task since a successful archive strategy requires the coordination of policies, procedures, technology and reporting. While all of these components are equally important, the archive technology plays a pivotal role since the physical attributes of the storage media greatly influence polices, procedures and effective reporting.

Cost of Ownership Analysis

In a recent study entitled "Active Archival Storage, A Cost of Ownership Analysis" the Enterprise Strategy Group (ESG) performed a third party analysis of the cost of acquisition and ownership over three years of operation between optical and disk archival technologies. The study concluded that the cost of a UDO-based solution is competitive with and is a fraction of the cost of a disk solution. In fact, the ESG analysis revealed that 12 TB of parity-protected disk capacity is 361% more expensive than a comparably configured automated UDO optical library.

The study also examined administrative costs of the disk-based architecture compared to optical libraries. The report concluded that any perceived advantage in ease of use for the disk system is not justified by the additional overall system cost for a 12TB solution. "UDO libraries are definitely a compelling option from a cost of ownership basis," said Brian Garrett of ESG. "Both from an acquisition and an on-going cost point of view, UDO technology delivers considerable savings."

A closer look at the results reveals that the cost of a disk solution can become inflated significantly due to the price of software acquisition and maintenance. Proponents of disk-based systems might bring up the scalable capabilities of disk to counter the UDO cost effectiveness claim; however, an examination based on the cost of fully populated UDO libraries shows the cost of acquisition to be reduced by approximately 20%. A typical upgrade strategy for disk solutions depends on replacing components and migrating data on a semi-regular basis. An automated optical library is about one-third the cost of a comparable disk system, and since all of the media for the automated UDO solution is inside the library, there is no need for a system administrator to handle removable media.

Continued Advantages

The availability of Compliant Write Once UDO media creates even greater management flexibility. Operating with the same level of record authenticity as True Write Once media, Compliant Write Once adds the ability to physically destroy selected files. This capability can be essential to archive data sets with specific retention policies and where an organization's risk management policies call for the physical destruction of records at end-of-life.

The technical and financial advantages of professional optical technology for long-term record storage have convinced organizations worldwide to choose UDO as the foundation for their archival storage strategy. Such organizations include investment banks, on-line trading companies, multinational insurance companies, government institutions, healthcare delivery organizations, television and radio broadcasters, retail companies, engineering firms and many more. Organizations recognize the authenticity, longevity and financial benefits of optical technology for archive requirements and are making a long-term investment in UDO.

Steve Tongish is the director of marketing (EMEA) for Plasmon and is based in Cambridge, UK.

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