Missing GFS retention tags caused by full backup jobs exceeding 24 hours

Discovered Version：v9.0.0 SP3

Question

In the Backup Data > Details page, certain Full Backup restore points are missing their expected GFS (Grandfather-Father-Son) retention tags (e.g., 'W' for Weekly, 'M' for Monthly).

For example, if the GFS policy is configured to retain weekly backups every Friday, the Full Backups executed on Fridays fail to receive the 'W' tag, disrupting the long-term retention strategy.

Answer

Issue Description

Currently, the Vinchin backup system evaluates and applies GFS tags based on the Task End Time rather than the Task Start Time.

If a target virtual machine contains a massive amount of data, the Full Backup process may take more than 24 hours to complete. If a job is scheduled to start on Friday but finishes on Saturday, the system evaluates the end time (Saturday) against the configured GFS policy (Friday). Because they do not match, the system bypasses applying the GFS tag.

Resolution

This issue can be resolved by utilizing the system's internal "Waiting Flag" mechanism.

Schedule an Incremental Backup to run on the designated GFS day, ensuring it executes before the long-duration Full Backup begins. The system recognizes the correct timeframe but notes it is not a full backup, thereby assigning a hidden "Waiting Flag" to that incremental point. Consequently, when the subsequent lengthy full backup eventually completes—even if it finishes on a different day—the system detects this flag and correctly applies the required GFS tag (W/M/Y) to the full restore point.