Microsoft Windows Updates and Scan Performance

This blog has seen a fair amount of activity regarding the ITMU/CPU scan issue recently surfaced for SMS 2003 which caused CPU stalls and performance issues.  Two distinct issues have been confused into what has often been viewed as a single problem and which has further been confused by what should be an expected CPU usage of up to 100% during the Scans.


This can become confusing so please stay with me as I attempt to disentangle the underlying issues, solutions, and alert you to an update which is on the horizon for the ITMU.


Performance Stalls:
The first issue involves performance stalls during the scan where the system performing the scan locks up and is unusable until the scan completes.  This issue has been resolved per the information contained in KB 924148.  With the CAB file changes introduced in the August CAB file release the issue which caused the Stalls or Hangs should no longer occur.  This information has previously been noted on this Manageability  blog.


Performance Duration:
The second issue involves the performance duration where scans can take an excessively long period of time to complete.   This issue is independent of the SMS CAB file issue and is  detailed in KB 916089 which was published on October 16th.  Performance improvements which are independent of changes to the SMS ITMU Scan Tool may be realized by updating the  MSI.DLL update per this KB article.

·      KB 916089:  FIX: When you run Windows Update to scan for updates that use Windows Installer, including Office updates, CPU utilization may reach 100 percent for prolonged periods


CPU Usage:
Finally, the 100% CPU issue.  This usage is expected.  As previously noted in this blog and in the Knowledge Base, the fixes provided by the CAB file changes per KB 924148 will not address the CPU usage numbers as scanning is a very CPU intensive process.  Regardless of the CAB file being used, the scan technology,  or the presence of the MSI.DLL update from KB 916086, scanning will likely continue to consume the available CPU.  This should be fine as with the change to the CAB file structure and through the updated MSI this usage should no longer trigger a system hang and should be of a reduced duration. 


But this is not the end of the story. 


ITMU Update:
With the changes introduced to the CAB file to address CAB file limitations an ITMU update will be needed.   Details of the pending update are noted in KB 926464.

·         KB 926464 A new version of the Windows Update offline scan file is being released


This has an impact across current scan and patch solutions and while the release date of the update is not yet clear, we wish to provide you as much early warning as possible.  Please review KB 926464 to understand what you can do now to prepare for the expected November release. 

Comments (3)

  1. Anonymous says:

    From April Cook: For those that are still experiencing performance issues, I am curious if you had also

  2. Anonymous says:

    This blog has seen a fair amount of activity regarding the ITMU/CPU scan issue recently surfaced for

  3. Anonymous says:

    thank you

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