EMC PowerPath Version Mismatch Between Cluster Nodes

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at http://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2007-07-25

The Microsoft Exchange Analyzer Tool reads the following registry entry to determine the EMC PowerPath version installed on each node in the cluster:


If the Exchange Analyzer finds that the value of the second or subsequent node in the Exchange cluster differs for Version, from the value for Version on the first node in the Exchange cluster, an error is displayed.

This error indicates that the nodes in this Exchange cluster are not running the same level of EMC PowerPath driver. As a best practice, we recommend that all nodes in an Exchange cluster run the same level of EMC PowerPath driver.

EMC PowerPath is multipath I/O (MPIO) software. Multipathing provides for high availability data access by allowing a host to have up to 32 paths to access an external storage device, which facilitates failover and load balancing. Multipathing is not a feature of the operating system, but is supported through the MPIO Driver Development Kit (DDK), which provides a means for storage vendors to create inter-operable multipathing solutions.

When MPIO software is run, Microsoft Windows detects only a single drive while the MPIO software manages the multiple connections to various storage devices. If the MPIO driver is mismatched between different nodes of the cluster, it could lead to cluster failover problems.

To resolve this problem, you must upgrade all nodes to the same EMC PowerPath driver version.

For More Information

For more information about deploying different storage technologies with Windows, see "Planning to Use Windows Storage Features with SANs" (http://go.microsoft.com/fwlink/?LinkId=33626).