Knowledgebase: Using tape drives
What is recycling and how does it work
Posted by Sven Koester on 23 April 2007 10:15
Q: How is the expiration date for volumes calculated?|
A: The expiration date of a volume is set when the volume is involved by a backup plan. It is calculated based on the number of cycles chosen and the schedule of full backups defined in the plan. E.g. if a full backup is set up for Monday and Thursday and 1 cycle should be maintained, then a plan running on Monday will set the expiration date to Thursday. Several plans with different schedules can use the same pool, but the expiration date will never be set back, only forward, to reflect the longest period the data must be maintained. The current backup cycle of any plan will not be overwritten regardless of the expiration date setting.
Q: Which recycling policies are available?
A: There are two possible recycling policies:
Q: When is the volume set to closed?
A: Written volumes are deemed "closed" when the pool is configured to use new volumes when starting a new full backup. The moment a plan employing such a pool is initiated, any volumes that have previously been written to, but are not yet full, will be closed. Closed volumes are recycled the same way as full volumes.
Q: Why are my volumes not automatically recycled?
A: Volumes are not recycled for one of the following reasons: