When you make an incremental backup, only the difference with the last increment is stored, you optimize your storage needs and profite from a better backup performance.
The feature is available using the option
--incremental in CLI - through API Volume V2 only.
To make an incremental backup of a volume, a classic backup is required. The Volume service retrieve all available backup for a volume, and will make an incremental backup, based upon the last created backup (which can be an increment or not). And so on.
A backup which is used to make an incremental backup can’t be deleted.
To know if a backup is incremental or if a backup has multiple incremental backups, you can use
cinder backup-show command.
We encourage you to make an incremental backup as soon as you have made changes to your volume: the more incremental backups are made, the more efficient the operation will be.
To avoid a chain of incremental backups, which can not be deleted, we strongly advise you to do a normal backup every 5 to 10 iterations.
If you wheel to use this feature, an adjustment of you quotas is maybe needed : default quotas are not scoped for this feature.
You can contact our support service firstname.lastname@example.org