Enforcing a retention rule
The frequency at which a retention rule is applied should be a major consideration. If you define an extremely granular retention rule such as time-based retention with rules for daily, weekly, monthly, and yearly retention that apply to a backup set with data from a long period of time online (like 10 years). This type of retention works best when applied only once.
If you apply it again, the next day, even if changes have been made in the past 24 hours and backed up, the other retention rules (weekly, monthly, yearly) will probably not capture data fitting the policy. By applying the rule only once, you can make it as ‘granular’ as you want, based on your knowledge of the data online.
Regular retention, such as weekly scheduled enforcement is more effective with retention rules that do not contain rule intervals longer than the frequency of enforcement. This means if you enforce retention weekly, it is best not to have rules for intervals longer than one week.
You must also consider the frequency of data changes.
To enforce a retention rule on a backup set on demand:
1. Click the Backup Sets tab.
2. In the tree, select the backup set on which you want to enforce retention.
3. On the Retention menu, click Enforce Retention.
4. In the confirmation dialog box, click Yes.