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Target Hypervisor

Long Term Retention Behavior After Changing the ‘Keep For’ VPG Setting

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An administrator may wish to update the 'Keep For' value of a given VPG's LTR configuration and may need to know the expected behavior of the previous retention sets.

Root Cause

The 'Keep For' setting is applied to a retention set when the scheduled or manual backup is run. If the 'Keep For' setting is changed after the scheduled or manual backup is run, the new 'Keep For' setting is applied to any new retention sets created. The expiration date of previously created retention sets cannot be changed.

In the example retention configuration provided above, the first two monthly backup retention sets had a 'Keep For' value of 12 months, and the next two had a 'Keep For' value of 2 months. The total amount of monthly retention sets will not be reduced to 3 until 12 months after the first monthly retention set was created, and will not be reduced to 2 until 12 months after the second monthly retention set was created.


As an example, an administrator may be using the default retention configuration of Daily Backup: Keep For 7 days, and Monthly Backup: Keep For 12 months.

After two months, the administrator may decide they do not want the Monthly Backup data to be kept for 12 months and changes the 'Keep For' setting to 2 months. Two months after changing the settings, the administrator observes there are 4 monthly backup retention sets available for this VPG.

Note: Retention sets left over from deleted VPGs are not managed, and are not removed from the LTR repository when the 'Keep For' date and time are reached. Therefore, deleting and recreating a VPG is not a valid workaround to reduce consumption in the LTR repository.


Below are some steps to clear out the stagnant retention sets leftover after making such a change:

  1. Estimate the size of the LTR repository before enabling LTR.

    1. The Zerto Scale and Benchmarking Guidelines document contains LTR sizing guidance. Using this document, an administrator can get estimates of their full and incremental retention sets. Using this information, an administrator can then size their repository accordingly.

  2. Add space to the storage used to host the LTR repository or migrate the repository to a storage system with more available space as needed.

  3. Delete the repository and change the LTR retention settings to consume less space.

  4. If a customer has not sized their repository before creating retention sets, runs out of space in the LTR repository, and cannot wait for the data to be removed on the expiration date of the retention sets, then the LTR repository can be deleted and recreated to reclaim this space.