We have Exchange 2007 CCR running in production environment. We are introducing new storage wherein we would move the user mailboxes. I ran the Jetstress test on the volume from the server itself and it shows Avg. Disk sec/Write in red. I would be glad if someone can provide suggestion on how can I make sure that the results I have is correct. I have been informed that Jetstress should not be run on server where Exchange is installed. But since we already have it running, I would like to know how can I address this issue and make sure the storage is configured properly. Fazal Ur Rehman Shah | Senior Consultant

Hi Fazal, Jetstress testing should be performed before you install Exchange on the server. There are some well-known risks associated with running Jetstress on a machine with Exchange installed. There are two primary risks associated with running Jetstress on a machine with Exchange installed. The first has already been discussed (Jetstress could potentially delete some existing logfiles if it's configured to use the same log drives that Exchange is using). The second is that if you use a version of Jet (ese.dll and eseperf.*) that is different than the version installed with Exchange, you'll end up registering the Jet database counters in the Jetstress install directory which will cause the database counters for Exchange to be broken after Jetstress is removed. Hope it helps.Rowen TechNet Community Support

Hi Rowen, Thanks for the suggestions. But it seems I have not been clear. We have bought new storage and want to move all user mailbox to this storage with increased mailbox quota. I need to perform Jetstress on this volume to make sure that it meets the performance requirement. What I have done is presented the LUNs to the server. Initiated & formatted it. Installed Jetstress and copied the required files. Ran the test of all 10 volumes of which only 3 failed. Though I have been informed that Jetstress should not be run on server where Exchange is installed. I want to know how can I make sure that the LUN configure meets performance requirement. Can I present this volume to another server and run JetStress there or is there any other way.Fazal Ur Rehman Shah | Senior Consultant

Hi Fazal, That information is in the field guide. http://blogs.technet.com/b/exchange/archive/2011/04/29/jetstress-field-guide-april-2011-release.aspx Appendix E – Running Jetstress on a production server Although the formal support position on this is that you shouldn’t do it – ever – at all – under no circumstances – in fact you shouldn’t even be reading this section of the field guide  … however, we all accept there are cases where it can be necessary, such as when attaching new storage to an existing server or troubleshooting performance bottlenecks on existing servers. That still doesn’t mean it’s ok to do it!! If you really MUST do it, here are some things to know before beginning… • Record the start-up state of all Exchange Services. • Stop and Disable all Exchange Services on the server. • Copy the ESE files from the currently installed version of Exchange server – Jetstress will detect that the performance counters are already installed for this version of ESE and will use them, this will prevent performance counter problems afterwards! • Do not unload/reload performance counters after the test (if you have used the same ESE files as are currently installed this is unnecessary and could break things!). • Remember to clean up the Jetstress test databases after testing. • Uninstall Jetstress. • Set Exchange Services back to the state they were in before you began testing. • Reboot your Exchange Server. • Inspect Exchange Performance counters are working. • Inspect Windows System and Application Event logs for errors. Remember: This is not supported or recommended – only follow this as a matter of last resort or under the instruction of Microsoft Support/Microsoft Consulting Services.Rowen TechNet Community Support

I want to throw in too that Appendix A will give you an idea of how many threads Jetstress can run and how many total IOPS that thread count will give you. Once you have the environment staged as Rowen mentioned, you'll want to select the number of threads based on how many IOPS the Storage Calculator recommends, then if it passes, increase it by 1 until it fails, or if it fails, decrease it by 1 until it passes.