Data Accessing and Archiving

Without a structured plan in place to address document and image storage and long-term preservation, an organization's valuable information assets are left vulnerable to loss, theft and inadvertent destruction.

Storage media refers to the format in which information is stored. This can range from stone tablets or paper for "hard copy" to a broad range of digital storage systems-many of which are more obsolete than the stone tablet.

Paper

Issues of paper storage have plagued records managers for centuries. In addition to the risk of loss or theft, paper must be protected from the elements. Fire, moisture and countless living creatures can render paper useless. Even the level of acidity in or around paper will, over time, cause irreparable harm.

Archival storage of paper documents is a science unto itself. Information capture professionals facing the need to store large volumes of paper would be well served to enlist the services of a professional records storage company or seek counsel from certified archivists.

Microimages

The use of microfilm and microfiche, or microimages, as an archival storage medium has been largely displaced by digital archiving. However, microimages are still far from obsolete. In some applications, microfilm and microfiche storage satisfy a requirement to maintain records in a human-readable form. In these instances (insurance record archives, for example) records are kept both digitally and in microimage form.

And while fewer records are being actively stored on microfilm, vast libraries of archival material are still stored in this format. This presents an opportunity for service bureaus that offer microimage conversion (to other media formats) services. The conversion of microform archives to digital form is expected to play an important role for some time. Traditional microfilm manufacturers have developed products for this conversion, as well as tools to "dual archive" by creating both film-based and digital storage.

Magnetic Disks

Information stored on individual hard drives, or on a shared file server is stored on magnetic discs. Magnetic storage provides very fast read/write speeds and immediate access because the media is always online. However, information is more vulnerable to change or loss as magnetic drives are inherently rewritable.

Data stored on a RAID (Redundant Array of Inexpensive Disks) storage system is likewise readily accessible, but offers increased fault tolerance. Information can be duplicated over multiple discs giving better protection from loss.

A third magnetic storage option is content-addressable storage. This technology creates a digital fingerprint of data as it is stored on the device. The fingerprint can be used to verify that the data has not been changed or deleted since the initial storage operation.

Finally, there are a host of removable magnetic storage options available, such as the USB stick drives that provide up to 4 GB of storage in a very compact form factor, often the size of a pack of gum. A number of manufacturers offer external hard disks in increasingly smaller form factors and in a variety of sizes, from several hundred megabytes to 40GB or more. These media are challenging for organizations to manage from both a security and records management perspective.

Optical Disks

Compact Disk (CD), Magneto-optical (MO) and DVD systems each use optical storage technology. CDs offer 650-700 MB of storage per disc, and can be either write-once (CD-R), or rewritable (CD-RW). The relatively small storage capacity-by today's standards-is offset by the advantage of being ubiquitous (nearly every PC is equipped with a CD drive, making them universally readable). Optical disks provide significantly slower data write and retrieval speeds compared to magnetic media.

DVDs provide a storage capacity of 4.7 GB, while dual-layer media provide a storage capacity of up to 8.5 GB. There are several different varieties available, including DVD-R/RW and DVD R/RW. The two formats are not compatible, but many readers support both formats, particularly those that carry the DVD Multi logo or that provide "DVD /-R/RW" support. A third format, DVDRAM, uses the same size disks but encloses them in a protective cartridge, providing more robust storage. DVD readers are backwards compatible and can read CD-ROM, CD-R, and CD-RW disks.

MO systems offer storage media enclosed in a protective cartridge, which can protect the disks from damage. Offering up to 9.1 GB per media, these systems are often chosen for long-term storage of large data volumes. MO has the advantage of durability and a faster access time than that offered by other optical storage systems, but they are not as common and are more expensive.

The next generation of optical storage is already available from several vendors. These systems are based on blue-indigo lasers and can store 23 GB on a single-sided 120mm disk (Sony PDD) or 30 GB on a dual-sided 130mm disk (Plasmon UDO). Because of these differences and others, the various technologies are not compatible. Like MO, these technologies use cartridges to provide increased protection against contamination and damage; the roadmap calls for storage of more than 100 GB per disk by 2007 and availability of media that does not use cartridges.