Which backup strategy is most efficient for large quantities of mission-critical data in a continuous operation environment?

Implementing a fault-tolerant disk-to-disk backup solution is the most efficient strategy for large quantities of mission-critical data in a continuous operation environment. This method allows for real-time data backup, meaning that data can be saved continuously as it is created or modified. The fault-tolerant aspect ensures that if one disk fails, the system still has access to the data from another disk, minimizing downtime and preventing data loss.

This strategy is particularly suited for environments where data availability is critical and where interruptions can lead to significant operational impacts. The disk-to-disk approach also generally facilitates faster recovery times compared to tape backups, which can be cumbersome and time-consuming. Furthermore, it offers more flexibility and scalability compared to other methods like creating duplicate storage or server infrastructure at a hot site, which require substantial resources and planning.

In contrast, making a full backup to tape weekly could lead to gaps in data protection since any changes made after the last backup would not be captured until the next scheduled full backup. Likewise, creating a duplicate storage area network or setting up identical server infrastructure at a hot site can be complex and costly and may not provide the immediate efficiency benefits required in a continuous operation scenario.