Symptoms
When you perform disk I/O operations on a Windows 2012-based computer, it takes longer than expected to determine performance or unresponsiveness issues.
Note A common cause of I/O latency issues is faulty or underperforming drivers. These latency issues specifically occur in disk or filter drivers. Disk drivers are typically associated with third-party Storage Area Network (SAN) products. Filter drivers typically are associated with antivirus, security, or encryption products.
Resolution
Cumulative Update information
To resolve this issue, install the Windows 8 and Windows Server 2012 cumulative update 2822241. For more information about how to obtain this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:
2822241 Windows 8 and Windows Server 2012 cumulative update: April 2013
After you install this update, you can log an event when the latency time for I/O to storage is equal to, or greater than, a threshold. The threshold value can be set by the user. This operation is performed at the Adapter Driver level so that you can see if there is a performance issue on the SAN. Then, you can contact a storage vendor to address the issue.
Note This update restores the functionality that was provided in Windows 7 and Windows Server 2008 R2. When the functionality is enabled, the threshold value is measured in 100 nanoseconds (0.0001 milliseconds). Additionally, the following values are logged in the event:
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BuildIoDuration: <Length of time that the MINIPORT has spent in the build I/O function for this request>
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StartIoDuration: <Length of time that the MINIPORT has spent in the start I/O function for this request>
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DataTransferLength: <Size of the transfer in bytes>
More Information
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates For more information about the issue in Windows Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base:
978000 Add a fix to improve the logging capabilities of the Storport.sys driver to troubleshoot poor disk I/O performance in Windows Server 2008 R2
