Where should tape fit into a contemporary backup/archive strategy?
Ian Lock: Despite all those cons, tape does still fit into a contemporary backup and archive strategy in a couple of key areas. Firstly, it still makes sense for long-term storage of large volumes of data. By long-term, we really mean those month-end or quarterly backups that have to be kept for maybe five or seven years. It makes very little sense to keep these large static backup images on disk, consuming power, cooling and maintenance budget when the data is accessed so infrequently. A sensible strategy will keep daily and weekly backups (those with shorter retentions) on disk for the first month or two, with monthly and quarterly backups, then kept on tape and held offsite. To provide protection from disaster, the daily and weekly backups on disk should ideally be replicated to a second site. This can be achieved in several different ways, either through an option of the backup application, through array replication or through advanced functionality of an intelligent virtual tape l