A Simple Strategy for Data Survival
The 3-2-1 rule is a simple, memorable, and powerful strategy for ensuring data redundancy and disaster recovery. On a modern film set, where the footage captured is the single most valuable asset, losing the original camera files is a production-ending catastrophe. The 3-2-1 rule is the industry-standard methodology employed by every professional Digital Imaging Technician (DIT) and data manager to prevent this from ever happening.
Breaking Down the Rule
The strategy is a straightforward recipe for creating robust backups:
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THREE Total Copies of Your Data
- The original data on the primary media (e.g., the camera’s memory card).
- A first backup copy (often on a high-speed RAID storage array on the DIT cart).
- A second backup copy (on a separate drive or set of drives).
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On TWO Different Types of Media
- This protects against a specific technology failing. For example, the primary media might be solid-state (CFexpress or SD cards), while the backups are on spinning hard disk drives or, for long-term security, on LTO magnetic tape.
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With ONE Copy Stored Off-Site
- This is the most critical step for disaster recovery. It protects against a localized event like a fire, flood, or theft at the primary location. At the end of each shooting day, a set of backup drives (known as ‘shuttle drives’) is physically transported to a secure, separate location, such as the production office, a local post-house, or a hotel safe.
By adhering to this rule, a production ensures that no single point of failure—a dropped drive, a corrupt card, a stolen bag—can lead to the permanent loss of their irreplaceable footage.