SnapProtect - Data Aging
Data Aging is the process of removing old data from secondary storage to allow the associated media to be reused for future backups.
By default, all backup data is retained infinitely. However, you should change the retention of your data based on your needs. Note that if you continue to have infinite retention, you will also need infinite storage capacity.
Setting Up the Basic Retention Rule
- From the CommCell Browser, expand Policies | Storage Policies | <Storage Policy>.
- Right-click the appropriate storage policy copy, and then click the Properties.
- In the Copy Properties dialog box, click the Retention tab.
- Under Basic Retention Rule for All Backups, click the Retain For.
- Enter number of days to retain the data.
- Enter number of cycles to retain the data.
- Click OK.
- In the Confirm Basic Retention dialog box, click Yes.
On the ribbon in the CommCell Console, click the Reports tab, and then click Forecast.Under Reports pane, Data Retention Forecast and Compliance is selected by default.
- Click Run.
- The report will display the data to be pruned when a data aging job is run.
To ensure only data intended for aging is actually aged, it is important to identify the data that will be aged based on the retention rules you have configured. Hence, ensure this report includes only the data you intend to age.
If necessary, fine-tune your rules so that only the intended data is aged.
Once you run a data aging job, the data will be pruned.
Running the Data Aging Job
- From the CommCell Console, right click the CommServe node, point to All Tasks and then click Data Aging.
In the Data Aging Options dialog box, click OK.
- You can track the progress of the job from the Job Controller window. When the job is completed, in the Job Controller the Status will be displayed as Completed.
Make sure that the job completes successfully. If the job did not complete successfully, rerun the job.
Extended retention rules can be used in the following circumstances:
- If you have a single drive tape library
- If you want to create a hierarchical retention scheme (grandfather-father-son tape rotation)
Extended retention rules allow you to define three additional "extended" retention periods for full (or synthetic full) backups. For example:
- You may want to retain your weekly full backups for 30 days.
- You may want to retain your monthly full backup for 90 days.
- You may want to retain your yearly full backup for 365 days.
A backup job will be selected for extended retention based on its start time. For example: If a backup job starts at 11:55 pm on August 31st and ends at 1 am on September 1st, then it will be selected as the last full backup for the month of August and will be picked up for extended retention.
In all other cases, we recommend you to use Auxiliary Copy for extended storage as it actually creates another physical copy of the data, thereby reducing the risk of data loss due to media failure.
Setting Up Extended Retention RulesUse the following steps for setting up the extended retention rules:
- Right-click the storage policy copy and click Properties.
- Click the Retention tab.
- Set the basic retention rules by clicking Retain for and entering the number of days and cycles appropriate for your organization.
- Set the extended retention rules as follows:
- Click the For button.
- Enter the number of Days Total to retain the backup.
- Click the Keep drop-down list, and select the desired backup criteria (e.g., Monthly Full, Weekly Full).
- Click the Grace Days drop-down list and select the number of days (e.g., 2).
This allows you to consider the additional number of days along with the Extended Retention rule. For example, if the last full backup job fails with in the defined extended retention criteria, then the next full backup job that ran in the specified grace days will be selected for retention.
- Repeat Step 4 to configure additional extended retention.
- Click OK.
- Log backups are linked to a full backup if they are run at the same time. This is regardless of whether the full backup included data only or data and logs. Such backups follows the standard data aging rules.
- If a full backup job is run on data and logs, then the next log backup will not be linked to this full backup job. These are unlinked log backups and by default, this will follow the unique data aging rules for log backups as given below:
- Logs that need to be copied to secondary copies will not be aged both on primary and non-primary source copy
- Logs that exist only on one copy will be aged when they are older than the oldest data
- When logs exist on multiple copies, the logs on the copy with longest retention days will be retained with the data and will be aged after the oldest data. The log jobs on the remaining copies will be aged according to copy retention days without checking if the oldest data exists or not.
- Partial, disabled logs will be aged when they are older than the oldest data
- If a full backup job is run on data, then the next log backup job will be linked to this full backup job. These are considered as linked or chained log backups and are not aged until the linked data is aged. In addition, these log backups will also follow the unique data aging rules for log backups.
Pruning All Log Backups By Days Retention Rule
By default, log retention rule is enabled. However, if old data exist in any of the storage policy copy , the log snaps are not pruned. In such cases, disable the log retention rule or run backup copy operations on the data jobs.
Use the following steps to disable log retention rule and enable unlinked log backups to be aged according to the defined days retention rule for the data. Note that when you define the days retention rule, use the same storage policy or retention criteria used for traditional rman backup, backup copy, and traditional rman log backup operations.
For example, consider the following subclients:
- Clone subclient using clone storage policy
- Snap subclient using the snap storage policy
- Log subclient using the log storage policy
The clone jobs using backup copy are run daily, snap jobs without backup copy are run every hour, and regular log backup jobs are run every 15 minutes.
When you disable log rule, make sure the retention for log storage policy primary copy is same or higher than the retention set for clone storage policy primary copy. Alternatively, you can also assign the same clone storage policy for archive log backups.
- From the CommCell Console, click the Storage tab.
- Click the Media Management icon.
- Click the Data Aging tab.
- In the Prune All Database Agent Logs Only By Days Retention Rule, type 1 to enable pruning for all database agent logs based on the days retention.
- Click OK.
Provides comprehensive information on additional Data Aging capabilities.