JetStress (WR2.2): Unhandled Exception: Cannot read Instance : F:MDBSG1

I have come across System.InvalidOperationException: Cannot read Instance : F:\MDB\SG1.

From memory dump analysis with the .NET perf. team, the main cause was either one of these:

• Some logical disks are not fully ready to use in the Windows PDH library.
• Something went wrong in the .NET perf. library (maybe thread-safety issues).

See the following example:

12/22/2005 9:32:10 AM -- Start tuning process, this may take an hour depending on the testing environment...
12/22/2005 9:32:10 AM -- Exception thrown during data collection. Error: System.InvalidOperationException: Cannot read Instance :F:\MDB\SG1.
   at System.Diagnostics.CounterDefinitionSample.GetInstanceValue(String instanceName)
at System.Diagnostics.PerformanceCounter.NextSample()
at System.Diagnostics.PerformanceCounter.NextValue()
at Microsoft.Exchange.JetStress.Performance.JetPerfInfo.Collect()
at Microsoft.Exchange.JetStress.MainForm.collectPerfData(Int32 runTime, Int32 interval, Boolean bRunForever)
12/22/2005 9:32:10 AM -- Exception thrown during tuning. Error: Cannot read Instance :F:\MDB\SG1.
12/22/2005 9:32:10 AM -- Performance logging stopped.
12/22/2005 9:32:10 AM -- Tuning process couldn't find suitable parameters, please use the suppress tuning to specify parameters.

Reference

• Volume mount points on disks in a server cluster may intermittently become unavailable after you install Windows 2003 SP1

This posting is provided "AS IS" with no warranties, and confers no rights.