A hotfix is available that improves the logging capabilities of the Storport.sys driver to troubleshoot poor performance issues for the disk I/O in Windows Server 2008

On a Windows Server 2008-based computer or on a Windows Vista-based computer, it takes a long time to troubleshoot slow performance or unresponsiveness issues that occur when you perform disk I/O operations.

The most common cause of I/O latency issues is drivers that are faulty or underperforming. Specifically, these latency issues occur on disk drivers or on filter drivers. Disk drivers typically are associated with third-party Storage Area Network (SAN) products. Filter drivers typically are associated with antivirus, security, or encryption products.

To resolve this issue, install the following hotfix. By using this hotfix, you can log an event when the latency time for I/O to storage is equal to or greater than a threshold. The user can set the threshold. This operation is taken at the Adapter Driver level so that you can see whether there is a performance issue on the SAN. Then, you can contact the storage vendor to address the issue.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, your computer must be running one of the following operating systems:

• Windows Vista Service Pack 1 (SP1)
• Windows Vista Service Pack 2 (SP2)
• Windows Server 2008
• Windows Server 2008 Service Pack 2 (SP2)

For more information about how to obtain a Windows Vista service pack, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Vista and Windows Server 2008 file information notes

Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows Vista" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

  Version	Product	SR_Level	Service branch
  6.0.600 0 . 20xxx	Windows Vista	RTM	LDR
  6.0.600 1 . 22xxx	Windows Vista and Windows Server 2008	SP1	LDR
  6.0.600 2 . 22xxx	Windows Vista and Windows Server 2008	SP2	LDR

• Service Pack 1 is integrated into the release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are very important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 and of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

For all supported IA-64-based versions of Windows Server 2008

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

After you install the hotfix, follow these steps to enable the System log when the latency time for I/O to storage is equal or greater than a threshold:

Command line version:

1. Click Start, type cmd.
2. Right-click the cmd icon, and then click Run as Administrator.
3. At the command prompt, type the following command, and then press ENTER:
   Logman.exe create trace Storport_Disk_IO_ETW_Trace -p Microsoft-Windows-Storport 8 255 -ets -o "c:\trace\Storport_Logging.etl"
   Notes
   • C:\ should be a drive letter where you have ample amount of disk space.
   • The directory that is specified must be created if it does not already exist.
4. Type the command "perfmon" at the command prompt to open the Reliability and Performance Monitor console.
5. In the Reliability and Performance Monitor (Perfmon.exe) console, locate the following item:
   Data Collector Sets\Event Trace Sessions
6. Double-click Storport_Disk_IO_ETW_Trace.
7. In the Properties list, click Keywords(All), and then click Edit....
8. In the Automatic list, click to select the IOPerfNotification check box, and then click OK.
9. In the Properties list, click Filter, and then click Edit....
10. Click to select the Filter enabled check box, then input a threshold value (measured in milliseconds) in hexadecimal format in the Filter data box, and then click OK
    
    Note Make sure that you set a hexadecimal value. For example, f would mean 15 milliseconds.
11. Click OK to save the Storport_Disk_IO_ETW_Trace properties.
12. Stop the data collector set after the I/O latency issue occurs. To do this, type the following command at the command prompt:
    Logman.exe stop trace Storport_Disk_IO_ETW_Trace -ets
    Note To start the trace again in the future, you can type the following command at the command prompt:
    Logman.exe start Storport_Disk_IO_ETW_Trace -ets
13. View the log by using the "Event Viewer" utility. Use the "Open Saved Log" function to open the "c:\trace\Storport_Logging.etl" file.
    
    Note It has to be viewed on a system with the same architecture (x86 or x64 or IA-64), the same operating system, and the same service pack level.

GUI Version:

1. In the Reliability and Performance Monitor (Perfmon.exe) console, click Data Collector Sets.
2. Right-click Event Trace Sessions, click New, and then click Data Collector Set.
3. Input a name for a new data collector set, select the Create manually (Advanced) option, and then click Next.
4. Click Add..., click the Microsoft-Windows-Storport item, and then click OK.
5. In the Properties list, click Keywords(All), and then click Edit....
6. In the Automatic list, click to select the IOPerfNotification check box, and then click OK.
7. In the Properties list, click Filter, and then click Edit....
8. Click to select the Filter enabled check box, then input a threshold value (measured in milliseconds) in hexadecimal format in the Filter data box, and then click OK
   
   Note Make sure that you set a hexadecimal value. For example, f would mean 15 milliseconds.
9. Follow the wizard to create the new data collector set.
10. Right-click the newly created data collector set, and then click Properties.
11. On the File tab, make sure that you have sufficient disk space to store logging.
12. Right-click the new data collector set, and then click Start.
13. Stop the data collector set after the I/O latency issue occurs.
14. View the log by using the "Event Viewer" utility. Use the "Open Saved Log" function to open the "c:\trace\Storport_Logging.etl" file.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information

Additional file information for Windows Vista and for Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported IA-64-based versions of Windows Server 2008