Troubleshooting Disk Queue Length

Published : September 27, 2005

If the performance of the DPM server is unacceptably slow, and you determine that poor disk performance is a contributing factor, perform the following steps to reduce the size of the disk queue.

To get more information about the performance of disk resources

To determine whether a disk bottleneck exists on the DPM server, you need to analyze patterns in the disk queue length in addition to disk usage, disk throughput, and the amount of paging that is occurring.

  • For more information about analyzing disk performance on a computer running a Microsoft Windows operating system, see the “Examining and Tuning Disk Performance” chapter in the Server Operations Guide of the Microsoft Windows 2000 Server Resource Kit.

  • For information about tuning disk performance on a computer running the Microsoft Windows Server 2003 operating system, see “Solving performance problems” in Help and Support for Windows Server 2003.

To resolve the immediate problem

  1. You may want to cancel some non-critical DPM jobs and running them later, when more memory is available.


    Canceling a protection job can compromise data protection. For more information, see “How to cancel a job” ( in DPM Help.

  2. If demand for disk resources does not subside, restart the DPM File Agent on the DPM server. In Administrative Tools, open Services. Then right-click DPM File Agent, and click Restart. When you restart the DPM File Agent service, all active jobs will be canceled.

To resolve long-term disk performance problems related to DPM jobs

  1. Tune disk performance on the DPM server. For more information, see “Solving performance problems” in Help and Support for Window Server 2003.

  2. Modify protection schedules for protection groups to stagger protection jobs. Consider offsetting some synchronization jobs from the beginning of the hour. You may also want to reduce the number of shadow copy jobs in the protection schedule. For more information about modifying protection schedules, see “How to modify protection options” ( in DPM Help.

  3. If disk performance continues to be a factor in degraded DPM performance, you may need to consider a hardware upgrade. For information about planning the disk configuration for a DPM storage pool, see the “Planning a Deployment” chapter in the DPM 2006 Planning and Deployment Guide (

  4. Check the configuration of antivirus software on the DPM server. For more information, see the “Managing Servers” chapter in this guide (