For Virtual Tape Libraries (VTL), when the data required for a restore or auxiliary copy job is not available in the disk pool cache, the data has to be fetched from the physical tapes. You can manually prefetch the tapes. Since the cache size is limited and might not accommodate all the tapes required for the restore or the auxiliary copy job, the prefetch is done as and when the data needs to be restored, which might lead to time delays. To avoid time delays during restores or auxiliary copy operations, you can configure to run the Prefetch Tapes for Restore workflow. This pre-defined workflow predicts the order of tape requirement and automatically loads it into the cache sequentially before it is required to be used by the restore or the auxiliary copy job.
This workflow requires a one time configuration, and then it is automatically executed when running restores or auxiliary copy from the CommCell Console.
Before You Begin
Ensure that you have the latest Service Pack installed on the CommServe.
Process Flow to Run the Workflow for Restore
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Deploy the workflow on the CommServe.
For more information, see Workflow Operations - Deploy a Workflow.
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Create an alert to trigger the prefetch workflow as follows:
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From the CommCell Console ribbon, click Home and then click Alert.
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From the Alerts dialog box, click Add.
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Type the alert name in the Display Name box.
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Select Job Management from the Category pane and Data Recovery from the Type pane, and then click Next.
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Select the Clients from the Entities Selection pane, and then click Next.
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On the Threshold and Notification Criteria Selection pane, select Job Started check box , and then click Next.
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On the Notification Types Selection pane, click the Workflow tab, select the appropriate options and click Next.
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From the Workflow to run list, select Prefetch Tapes for Restore.
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From the Run workflow on list, select the workflow engine where the workflow is deployed.
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Select <JOB ID> for the value column for variable jobId.
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Select the Init Count value to set the number of tapes to be prefetched. By default 4 tapes will be prefetched. More tapes will be prefetched as and when the prefetched tapes are used for restores.
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Select the Delay value. This is frequency (in seconds) to check if the prefetched tapes have been used. By default the check is done every 30 seconds.
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Review the alert selections and then click Finish.
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Process Flow to Run the Workflow for Auxiliary Copy
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Deploy the workflow on the CommServe.
For more information, see Workflow Operations - Deploy a Workflow.
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Create an alert to trigger the prefetch workflow as follows:
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From the CommCell Console ribbon, click Home and then click Alert.
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From the Alerts dialog box, click Add.
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Type the alert name in the Display Name box.
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Select Operation from the Category pane and Event Viewer Events from the Type pane, and then click Next.
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Select the Clients from the Entities Selection pane, and then click Next.
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On the Threshold and Notification Criteria Selection pane, type 19:1592 in the Event Code box , and then click Next.
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On the Notification Types Selection pane, click the Workflow tab, select the appropriate options and click Next.
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From the Workflow to run list, select Prefetch Tapes for Restore.
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From the Run workflow on list, select the workflow engine where the workflow is deployed.
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Select <JOB ID> for the value column for variable jobId.
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Select the Init Count value to set the number of tapes to be prefetched. By default 4 tapes will be prefetched. More tapes will be prefetched as and when the prefetched tapes are used for restores.
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Select the Delay value. This is frequency (in seconds) to check if the prefetched tapes have been used. By default the check is done every 30 seconds.
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Review the alert selections and then click Finish.
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What to Do Next
After deploying the workflow and configuring the alert, you can run restores to restore that data that was backed up on virtual tapes. The restore operation will trigger a prefetch for the relevant exported tapes.