Storage space and backup retention
Your protection strategy should include plans for retaining the necessary local backups to meet your RPOs and RTOs. The most comprehensive strategy involves retaining recent local backups for quick recovery, and copying these backups to an offsite target for long-term retention and disaster recovery.
To create space for new backups, Unitrends appliances periodically purge older backups. Retention policies control how long backups remain on the appliance. Backups held by a policy are never purged. New backups fail if an appliance cannot purge older backups to create sufficient space.
Retention settings assure that the necessary recovery points are available on your appliance. Appliances are configured with a default backup retention policy of 30 days. This 30-day policy is applied to each protected asset.
NOTES
● The 30-day default retention policy applies to appliances imaged with release 10.7.8 or higher. This default policy does not apply to appliances that were originally imaged with an earlier release. Upgrading an appliance that was imaged with a pre-10.7.8 release does not modify its retention policies in any way.
● The 30-day default retention policy ensures that 7 daily backups and 4 weekly backups are retained for each protected asset.
You can also create your own retention policies to hold backups for a specified number of days. You can create multiple policies and customize them to achieve different RPOs and RTOs for your assets. See Managing retention with long-term data management for details.
The amount of total backup storage capacity on the appliance varies by appliance type:
● Recovery Series, Recovery MAX, and ION/ION+ physical appliances come with a set amount of backup storage. You cannot add backup storage to the appliance.
● Unitrends Backup virtual appliances are deployed as virtual machines. During deployment, the initial backup storage was created using either a virtual attached disk, a SAN LUN, or a NAS share. After initial deployment, you can add more backup storage as desired. See About adding backup storage to a Unitrends Backup appliance for details.
This storage capacity is used to store local backups, for VM instant recovery, and for Windows replicas. To use the instant recovery or Windows replicas features, you must reserve a portion of this storage to be used for instant recovery write space. For more on storage, see Backup storage.
