In the recent weeks I've worked several cases where Exchange 2007 SP1 Single Copy Clusters with storage groups enabled for Standby Continuous Replication on Windows 2008 have had performance and network connectivity issues. These issues have manifested themselves with the following symptoms:
- Outlook clients appear to have no issues connecting to or using the Exchange instances.
- Access to the host machine console is slow. RDP may connect unreliably.
- Use of management tools may fail fail to connect, for example event viewer and failover cluster manager will fail to connect.
- Get-storagegroupcopystatus -standbymachine may report failed replication instances between source and target.
- Review of share management under server management shows that SCR shares are being deleted and recreated on the source cluster.
In each case the following was common to all the situations I worked.
- Operating system is Windows 2008
- Source cluster is an Exchange 2007 SP1 RU5 Single Copy Cluster (SCC)
- One or all storage groups are enabled for Standby Continuous Replication (SCR)
- Network interfaces drivers were older then July 2008.
- Network teaming was used on the public cluster interfaces and configured for Fault Tolerance with Load Balancing
- If standby continuous replication was disabled on any enabled storage group cluster stability could be maintained.
The following was performed to resolve the stability issues. Note: All steps are considered part of the solution.
1) Upgrade network interface drivers to a revision July 2008 or newer.
2) Reconfigure all network teams for Fault Tolerance Only.
3) Install KB 955733 to all clustered nodes.
This kb article corrects known issues with status codes returned by the Windows operating system for certain function calls. Note that when downloading the fix it is marked as Vista x64 although the fix is for Windows 2008 x64.
4) Open a case with Microsoft CSS - Request Exchange interim update KB957834. (Recommend that customers upgrade to Exchange 2007 SP1 RU5 and deploy the RU5 IU). This article can be found at: http://support.microsoft.com/kb/955733
This update is available for Exchange 2007 SP1 RU4 and Exchange 2007 SP1 RU5 at this time. This update corrects issues with share endpoint checking for servicing SCR. For more information regarding the replication service and shares see http://blogs.technet.com/timmcmic/archive/2008/12/23/exchange-replication-service-exchange-2007-sp1-and-windows-2008-clusters.aspx