What is GFS retention policy?

GFS retention, also as known as Grandfather-Father-Son retention. It is a long-term data retention policy which allows you to retain your VM backups for longer period of time using a minimal amount of storage resource.  Vinchin Backup & Recovery implemented GFS retention to retain the following backups for different periods of time respectively:

Weekly full backup 

Monthly full backup 

Yearly full backup 

For the weekly full backup, you can specify a day of the week on which the full backup is supposed to be created,  and specify for how long (how many weeks) to be retained. Then Vinchin Backup & Recovery will start to wait and  tag the first coming full backup of the week. The tagged full backup will be retained for the specified number of weeks, and the general short-term retention policy will not purge the tagged weekly full backup until the tag is  expired. As for the monthly and yearly full backups, GFS retention works the same way. 

GFS retention policy can be configured during the VM backup job creation process, when the job started to run regularly according to its schedule. The specific backups will also be tagged automatically as per your configurations. The tagged full backups (restore points) can be seen on the VM Backup > Backup Data page, the  tags can be added or removed manually on the same page if needed, but GFS retention only works with full  backups (full restore points). 

GFS retention works independently with the general short-term retention policy, so you can implement both general and GFS retention policies in a VM backup job. Additionally, for some specific backup restore points, you can manually tag them with the forever retention tag to keep them in the backup storage permanently.