Scheduling Consistency Checks

Published : September 27, 2005 | Updated : May 10, 2006

Because consistency checks affect the performance of both the DPM server and the file server, you should schedule consistency checks for hours when reduced responsiveness of the file server has the least impact on your business operations and there is the least amount of network traffic.

When you create a protection group, a consistency check is automatically performed as part of the replica creation process. After a protection group is created, if a replica becomes inconsistent because of a network outage, a synchronization log overflow, or another reason, you can perform a manual consistency check. For instructions, see "How to synchronize a replica" (https://go.microsoft.com/fwlink/?linkid=51910) in DPM Help.

You can also schedule a daily consistency check to ensure that inconsistent replicas are automatically repaired. A scheduled consistency check will only run if the replica is inconsistent. For example, on Sunday, you modify your protection group options to schedule a daily consistency check. From Sunday to Wednesday, data protection jobs are successfully completed and all replicas are successfully synchronized, therefore the daily consistency check does not run because all replicas are consistent. Then, on Thursday, a large number of new files are copied to a protected file server and the synchronization log on the file server runs out of space. The next regular synchronization fails, DPM generates a "replica is inconsistent" alert, and the affected replicas are marked as inconsistent. Because you have scheduled a consistency check, DPM performs the consistency check at the scheduled time and repairs the replicas.

As part of the scheduling options, you can configure a duration or time window when consistency checks jobs can run. For example, you can configure the consistency check to begin at 8:00 P.M. when most of your company’s employees are gone, with a maximum duration of 10 hours. If the consistency check does not finish in the specified 10-hour time window, DPM will pause the consistency check the next day at 6:00 A.M. At 8:00 P.M., DPM will resume the consistency check job. DPM will continue this pause and resume process every day until the consistency check job has successfully completed. For instructions to schedule a daily consistency check, see "How to modify protection options" (https://go.microsoft.com/fwlink/?linkid=51911) in DPM Help.

Note

A paused consistency check will be displayed as “Failed” in the Monitoring task area.

For information on scheduling considerations when the DPM server and the protected file server are in different time zones, see the “Managing Servers” chapter in this guide (https://go.microsoft.com/fwlink/?LinkId=46367).