Which backup strategy recommends maintaining three copies of data on two different media types with one copy stored offsite?

Which backup strategy recommends maintaining three copies of data on two different media types with one copy stored offsite?

• A. Version Control
• B. Differential Backup
• C. 3-2-1 Backup Rule
• D. Full Backup

Answer: (C)

The idea here is resilience through multiple copies and geographic separation. The three-copy rule plus offsite storage means you keep three total copies of your data: the primary data plus two backups. These copies live on at least two different media types to guard against failures that affect a specific media type (for example, a failed hard drive or a corrupted tape). Putting one copy offsite protects you from local disasters such as fire, flood, or theft that could affect everything on-site. This approach is the recommended practice because it provides redundancy, media diversity, and geographic separation in a simple, enforceable policy. It helps ensure you can recover even if one copy is damaged, one medium fails, or a disaster hits your location. Contrast this with common alternatives: Version control tracks changes to files over time, which is great for developers but isn’t designed to protect entire data sets or ensure offsite recovery. A differential backup saves only changes since the last full backup, which is efficient for backups but still doesn’t guarantee three copies on multiple media with offsite storage. A full backup copies everything, but by itself doesn’t address how many copies you have, whether they’re on different media, or whether any copy is kept offsite.

The idea here is resilience through multiple copies and geographic separation. The three-copy rule plus offsite storage means you keep three total copies of your data: the primary data plus two backups. These copies live on at least two different media types to guard against failures that affect a specific media type (for example, a failed hard drive or a corrupted tape). Putting one copy offsite protects you from local disasters such as fire, flood, or theft that could affect everything on-site.

This approach is the recommended practice because it provides redundancy, media diversity, and geographic separation in a simple, enforceable policy. It helps ensure you can recover even if one copy is damaged, one medium fails, or a disaster hits your location.

Contrast this with common alternatives: Version control tracks changes to files over time, which is great for developers but isn’t designed to protect entire data sets or ensure offsite recovery. A differential backup saves only changes since the last full backup, which is efficient for backups but still doesn’t guarantee three copies on multiple media with offsite storage. A full backup copies everything, but by itself doesn’t address how many copies you have, whether they’re on different media, or whether any copy is kept offsite.