Nonpaged pool kernel memory leak on Windows Server 2003 with Multipathing solution installed

When you use a multipathing solution on a Windows Server 2003-based computer, you may experience excessive use of the nonpaged pool memory. This excessive use could lead to depletion of the pool memory. This may cause the computer to stop responding (hang) or may cause an unexpected failover.�

Additionally, the following error is logged in the Application log:

Microsoft Multipath I/O (MPIO) version 1.21 had a memory leak that applied to both Fibre Channel storage and iSCSI Software Initiator implementations. This was fixed with MPIO version 1.22, and it is included in iSCSI Initiator package 2.08.

There was a new issue in MPIO version 1.22. However, this new issue applies only to some vendor Device Specific Modules (DSMs). The issue does not apply to the DSM that is used with the iSCSI Initiator package. The issue is addressed in MPIO version 1.23.

The issue in MPIO version 1.22 does not affect the DSM that is included with the iSCSI Initiator package. It was not necessary to update the initiator package again for the issue in MPIO version 1.22.

To resolve this issue, use one of the following methods, depending on how MPIO was obtained.

Method 1: Fibre Channel storage

If you use Fibre Channel storage, the MPIO binaries are distributed by the storage vendor with their DSM. Please contact the storage vendor to ask about an update that includes the updated MPIO drivers.

Method 2: iSCSI Software Initiator

If you use the iSCSI Software Initiator, apply the Microsoft iSCSI Software Initiator Version 2.08 package. For more information about how to obtain the Microsoft iSCSI Software Initiator Version 2.08 package, visit the following Microsoft Download Center Web site:

This issue affects anyone who uses the Mpio.sys driver in a clustered environment. The issue will be more pronounced when a larger number of Logical Unit Numbers (LUNs) are connected. You should first contact your vendor if you have concerns about your storage solutions or configurations.