Topic Last Modified: 2005-11-18

On a non-clustered Exchange Server computer, the Microsoft® Exchange Server Analyzer Tool reads the following registry entries to determine the value for the TEMP and TMP environment variables:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment\TEMP

HKLM\System\CurrentControlSet\Control\Session Manager\Environment\TMP

When the Exchange Server Analyzer is run against Exchange Virtual Server (EVS) in a Microsoft Windows® server cluster, it does not read HKLM registry hive. Instead, it reads the following registry entries:

HKEY_USERS \<Cluster service account SID> \Environment\TEMP

HKEY_USERS \<Cluster service account SID> \Environment\TMP

If the Exchange Server Analyzer finds that either the TEMP and/or TMP environment variable begins with %SYSTEMROOT, a warning is displayed.

The Microsoft Exchange Information Store service process uses the TEMP and TMP folders as temporary storage during various operations, such as message conversion and mailbox move operations. On a non-clustered Exchange server, the Microsoft Exchange Information Store service uses the SYSTEM (for example, Local System), which uses a default environment variable setting of %Systemroot%\Temp for both TEMP and TMP.

EVS running in a Windows server cluster uses the environment variable settings for the Cluster Service account, which runs under the context of a specific user security principle. For user accounts, the default environment variable for TEMP and TMP is set to %Userprofile%\temp.

The TEMP and TMP environment variables are used to designate which folders in the file system (for example, which path) should be used by applications that require a temporary workspace. TEMP is typically used by applications, such as Exchange, and TMP is typically used by development tools, such as Microsoft Visual C++®. The path for each variable is usually relative to the security context of the application or tool.

For optimal performance, it is recommended that you do not use the disk containing the operating system for the TEMP and TMP folders used by Exchange. In addition, you should ensure that these environment variables are set to paths on a fast disk or disk subsystem, such as a RAID 0+1 spindle set. It is also recommended that you do not use the disk containing the operating system for the TEMP and TMP folders used by Exchange or EVS.

To correct this warning

  1. Log on to a node in the cluster as the Cluster service account.

  2. Right-click My Computer and select Properties.

  3. Select Advanced.

  4. Click Environment Variables.

  5. In the User variables for <account name> area, select TEMP and click Edit.

  6. In the Variable value field, enter the new path for the TEMP environment variable and click OK.

  7. In the User variables for <account name> area, select TMP and click Edit.

  8. In the Variable value field, enter the new path for the TMP environment variable and click OK.

  9. Click OK to close the Environment Variables dialog box and OK once more to close the System Properties dialog box.

  10. Restart the node to apply the change.

  11. Repeat steps 1 through 10 for each node in the cluster.

For information about changing the TEMP/TMP environment variables on a non-clustered Exchange Server computer, see The TEMP/TMP variable appears to point to an invalid or inappropriate folder.