Simple definition
An Active Full Backup is a full backup created by reading the protected production data directly from the source again.
Technical definition
Unlike a synthetic full, which builds a new full from backup files already stored in the repository, an Active Full reads the required blocks from the protected machines or volumes and writes a new complete backup. It therefore places more load on the source, network, and repository during the operation.
How it works / role
Its role is to create a new full restore point without relying on the previous backup chain to read the source data. Depending on the backup product, it can also start a new incremental chain.
What is it used for?
Periodically create a fresh full backup, meet a specific protection policy, or rebuild the backup chain when the architecture and backup window allow it.
Practical example
A backup policy runs daily incrementals and a monthly Active Full. On full-backup day, all required data is reread from production and a new complete backup file is written.
Common issues
- High production I/O during the full backup
- Backup window becomes too long
- High bandwidth and repository-space consumption
- Confusion between Active Full and Synthetic Full
Related terms
Key takeaway: Schedule Active Full operations with production load in mind; a Synthetic Full generally reduces source reads but places more work on the repository.