It's a perennial debate, being given more urgency in the post-Sept. 11 era. Recently, Storage spoke with tape and NAS giant Quantum's chairman and CEO Michael A. Brown, and Barbara Hoey Nelson, executive vice president for corporate marketing and strategy to get their views.
Brown says Quantum surveys have shown that a full third of all tape backups never finish. It's those kind of statistics that are driving interest in disk backup. But Quantum has eschewed the pure disk-to-disk, file-to-file approach in favor of its DX-30 dedicated virtual tape appliance. The reason: more seamless integration with current tape backup environments.
Nelson says the experience of the 40 or so beta sites for the DX-30 is that storage managers keep backups on the DX-30 for a month. That window covers the overwhelming majority of restore requests. Then users archive the backups to tape for longer-term storage. Staging backups to disk first lets storage managers use a longer backup window.
Under this scenario, Brown thinks that users may ultimately buy fewer drives - a trend also driven by larger, more consolidated libraries and bigger drive capacities - but will buy more media as disk backup leads to a higher percentage of successful backups.