Optimising Your Backup With An Archive

Published 15th June 2007

By Steve Tongish, director of marketing (EMEA)

There are many approaches to improving the efficiency of your backup environment. Today, it often involves the use of sophisticated hardware and software tools that enable increasing volumes of data to be backed up and recovered in shorter periods of time. While these solutions offer many compelling benefits, seldom do they actually consider the data. One of the best ways to optimise your backup is to make sure you are backing up the right data.

The purpose of a backup strategy should be to offer an insurance policy against the unintended loss of “active” data. Active data can be defined as information that is being collected, modified or frequently accessed. It is during this stage that data is the most vulnerable and must be properly protected. However, once data moves into a “static” state, it can be removed from the backup process and stored in an archive. By definition, static data is no longer changing and requires less frequent access. Since the risk profile and business objectives change when data moves from an active to a static state, it is logical that the way it is protected and retained should also change.

In simple terms, why should you continue to backup the same unchanging static data 365 times a year? By most accounts, between 60% and 80% of all unstructured data is static. If only half of this data could be moved out of the backup cycle into an archive, it would have a dramatic impact on backup overhead. With much less data to protect, backup windows would be slashed, investment in sophisticated backup tools would be reduced, and IT resources could be reallocated. In addition, the implementation of an archive strategy allows businesses to more appropriately manage the long-term retention of their data.

A well-designed archive assists an organisation to meet industry regulation on data authenticity and retention periods, something that backup products are simply not designed to provide. Backup is a short-term insurance policy, not compliant long-term data retention. In other words, the purpose of backup is recovery and the purpose of archiving is discovery - two very different objectives.

Another advantage of implementing an archive strategy is the opportunity to move infrequently accessed static data off expensive magnetic disk, to less expensive storage. This can represent a huge savings if the correct storage hardware is selected. Simply moving your archive data to a less expensive RAID system will reduce acquisition cost, but it does not eliminate the backup overhead. All RAID systems are based on volatile spinning magnetic media that must be protected from catastrophic disk failure, making backup essential. Unfortunately, this puts you right back where you started with the need to backup your archive data.

Magnetic tape storage certainly provides a cost-effective archive option, but it is also a volatile media that can be damaged during handling, wears with use, and must be stored in proper environmental conditions to reduce the risk of data loss. Any archive using magnetic tape should be carefully monitored and exercised, with data periodically refreshed on new media. While this may not require the full backup of a tape archive, it does require significant additional cost and administration.

By contrast, professional optical storage such as UDO (Ultra Density Optical) is a non-volatile media. As a removable media, it is not at risk of catastrophic system failure such as RAID and uses a Phase Change recording technology that is far more stable than magnetic tape or disk. Unlike tape, UDO is also a non-contact media that does not wear with use and is much less sensitive to environmental conditions, requiring virtually zero maintenance. This means that by employing a UDO based archive for static data, you eliminate the need to backup the archive data. UDO storage technology can maximise the financial and administrative benefits of implementing an archive.

This raises the question of Disaster Recovery (DR). What happens if there is a site failure that physically destroys your archive? It is important to realise that this risk is independent of your choice to implement a disk, tape or UDO based archive. If your archive data is valuable, you should never have only one copy at a single site. A DR strategy that provides for one or more off-site copies of your archive data is essential, regardless of the archival storage media.

There is often confusion about the difference between backup and archive. Both pay a key role in the success of your business, but if used incorrectly they can be very inefficient. Backup resources should be focused on the protection of active data, and once data becomes static it should be moved out of the backup cycle into a dedicated archive environment. This illustrates just how complementary backup and archiving can be. An integrated backup and archive strategy offers tremendous efficiency and cost savings, particularly when non-volatile UDO archive technology is deployed.