Configure advanced options

Article
02/14/2008

Published : April 8, 2005 | Updated : August 17, 2005

When creating a protection group, you can modify the default settings for network performance, shadow copies, and consistency checks.

Setting performance options

DPM provides options to optimize network performance when running protection jobs as described in the following table:

Performance option	Description
Network bandwidth usage throttling	Limits the amount of network bandwidth that DPM can use to create and synchronize replicas. Throttling helps to ensure that network bandwidth is available to applications other than DPM.
On-the-wire compression	Allows more data throughput without negatively affecting network performance. However, this option does add to the CPU load on both the DPM server and the protected file servers. Compression decreases the size of data being transferred during replica creation and synchronization.
Specify start times for protection jobs	Makes it possible to manually stagger the start times for protection jobs by protection group, thereby avoiding the impact on network performance of running multiple large protection jobs simultaneously. This option is most useful when you have multiple protection groups. Note that DPM automatically staggers the start times of jobs across servers within a protection group. The protection jobs for each server are offset from one another by 10 minutes, so that the jobs of up to 6 servers are evenly distributed. If you are protecting more than 6 servers, jobs start to overlap.

Network bandwidth usage throttling

Limits the amount of network bandwidth that DPM can use to create and synchronize replicas. Throttling helps to ensure that network bandwidth is available to applications other than DPM.

On-the-wire compression

Allows more data throughput without negatively affecting network performance. However, this option does add to the CPU load on both the DPM server and the protected file servers. Compression decreases the size of data being transferred during replica creation and synchronization.

Specify start times for protection jobs

Makes it possible to manually stagger the start times for protection jobs by protection group, thereby avoiding the impact on network performance of running multiple large protection jobs simultaneously. This option is most useful when you have multiple protection groups.

Note that DPM automatically staggers the start times of jobs across servers within a protection group. The protection jobs for each server are offset from one another by 10 minutes, so that the jobs of up to 6 servers are evenly distributed. If you are protecting more than 6 servers, jobs start to overlap.

To set performance options

In the Modify Protection Options dialog box on the Performance tab, enable network bandwidth usage throttling by selecting Enable network bandwidth usage throttling.
Select the maximum speed for data transfers from the file servers to DPM.
To enable on-the-wire compression, select Enable on-the-wire compression.
To stagger start times for protection jobs, specify the number of minutes after the hour to start synchronization and shadow copy jobs.

Scheduling shadow copy jobs

You can create up to eight shadow copies of a synchronized replica within a 24-hour period.

Important

If you are protecting file servers in a time zone that is different from that of the DPM server, the times specified in the Modify Protection Options dialog are file server times.

To schedule shadow copy jobs

In the Modify Protection Options dialog box on the Shadow Copy tab, select the times of day and days of the week on which to create shadow copies.
To make sure that you meet your overall protection goals, review the data in the Estimated recovery goals area. This data changes dynamically as you specify the frequency and times for creating shadow copies.

Note

Shadow copy time is not the time when DPM creates a shadow copy. Rather, it is the point in time on the file server that the shadow copy represents. To ensure that a shadow copy reflects the state of a file server at the specified shadow copy time, DPM must synchronize the replicas with the file server before it creates the shadow copy. Depending on the synchronization schedule, shadow copy creation can take place several hours after shadow copy time.

When data change activity is high, schedule more shadow copies to minimize the risk of losing data. When data change activity is low, schedule fewer shadow copies. For example, you might want to forego creating shadow copies on Saturdays and Sundays if most changes to the data occur Monday through Friday.

Scheduling consistency checks

You can schedule a daily consistency check during off-peak hours to ensure that the replica is consistent with the protected data. A scheduled consistency check will only run if inconsistencies are detected during synchronization. Keep in mind that the performance of the file server will be affected while the consistency check is running.

Important

If you are protecting file servers in a different time zone than the DPM server, times specified on the Consistency Check tab are in file server time.

To schedule a consistency check

In the Modify Protection Options dialog box on the Consistency Check tab, select Schedule consistency check.
Specify the start time and maximum number of hours to allow for the consistency check.