Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2008-03-19
Before implementing a storage solution in a production environment, it is important that you validate that the solution is configured properly. This topic provides guidance for successfully testing a storage solution for Microsoft Exchange, beginning with a program that includes solutions that have already been tested. In addition, information is given about several tools that can help you manage, test, and monitor your storage solution.
When selecting a storage solution, we recommend you choose a solution that has been reviewed by the Microsoft Exchange Solution Reviewed Program (ESRP) 2.0 for storage, known as ESRP-Storage. ESRP-Storage is an Exchange-specific test, best practices publication framework, and review process to facilitate the creation of known, good Exchange storage solutions. The goals of ESRP-Storage are to:
Provide storage vendors with prescriptive guidance about Exchange storage testing and best practices publication.
Develop a mechanism to review storage solutions to make sure that they meet Exchange best practices.
Provide customers with well-tested and high-quality storage solutions targeted for Exchange deployments.
For more information about ESRP-Storage, see Microsoft Exchange Solution Reviewed Program (ESRP) - Storage.
|ESRP-Storage is not a Microsoft certification, qualification, or logo program.|
Because storage can be configured in many ways, evaluating tested configurations and using best practices can reduce costs and decrease the time to deployment.
Before testing a solution, some work is required to understand what it is you are trying to achieve by testing. Some of the keys to successful storage testing include:
Determine testing goals. For example, consider the performance, throughput, and capacity numbers needed.
Test with as many servers attached to the storage as you will have in production. This includes non-Exchange servers and workloads.
Test with production-sized databases with the physical disk capacities filled to production level. Most physical disk performance characteristics will change based on the data set size.
Determine that storage meets the transactional input/output (I/O) requirements, and determine the maximum performance of the solution within acceptable latencies.
Determine that storage meets the backup throughput and performance requirements to meet your backup and restore service level agreement (SLA).
The Microsoft Exchange Server Jetstress tool accurately simulates Exchange I/O characteristics. It includes both a stress test and a performance test, which show the maximum performance of a LUN within acceptable latencies. A new version of Jetstress has been created to support Exchange 2007. In addition, a replacement for Load Simulator has been created for simulating Microsoft Office Outlook clients. The replacement tool is called Exchange Load Generator.
Both tools simulate Outlook and require a fully configured Exchange 2007 environment for testing. Simulating Outlook clients is the only way to measure actual client latency (rather than just the server disk latency).
You can download both of these tools using the following links:
Exchange Load Generator:
The Exchange Stress and Performance tool is used to simulate Internet protocols such as POP3, IMAP4, and SMTP. It is often used to simulate incoming Multipurpose Internet Mail Extensions (MIME) mail from the Internet to an organization. You can download this tool using the following links:
- Exchange Server Stress and Performance Tool (64 bit)
- Exchange Server Stress and Performance Tool (32 bit)
Other useful tools can be found at Tools for Exchange Server 2007.
Monitoring your storage solution is critical in identifying hardware and software warnings and error conditions before they lead to data corruption or downtime.
The following tools can help monitor your storage solution. These tools are available in the Toolbox node of the Exchange Management Console:
Best Practices Analyzer Tool
Performance Troubleshooter Tool
In addition, you can also use Microsoft System Center Operations Manager 2007 and Microsoft Operations Manager 2005 to monitor your storage solution, as well as several other aspects of your Exchange organization.
Performance Monitor (perfmon.exe) is the Microsoft Management Console (MMC) performance snap-in for Exchange 2007. Perfmon, which uses the MSExchangeIS performance object to retrieve counter information, provides information that allows you to gauge the health of your storage solution. You can use the remote procedure call (RPC) average latency information provided by Perfmon to determine how disk latency may be affecting the client user experience. Disk latency counters should match the following criteria:
RPC average latency should be less than 50 milliseconds
RPC requests should be less than 30 requests at all times
Disk latency should be less than 10 milliseconds for log writes and less than 20 milliseconds for database reads and writes
On most storage solutions, there is a way to see performance metrics. Monitoring these metrics can catch performance issues before they effect Exchange. If available, Microsoft Operations Manager integration from the storage vendor can assist in making sometimes proprietary metrics easy to understand. Some of the general metrics to watch include:
- Disk Utilization Percentage How busy are the physical disks?
- Read Cache Hit Ratio How well is the storage controller cache being utilized?
- Write Pending Requests How often is the controller waiting for the physical disk?
- Storage Processor Utilization Percentage How busy is the storage CPU?