Topic Last Modified: 2006-09-01

The Microsoft® Exchange Server Analyzer Tool has determined that the TEMP and TMP folders for the server may not be located for optimal disk performance. As a best practice, it is recommended that the TEMP and TMP folders be stored on a disk subsystem that is not shared by your system folder or the Exchange data files.

The Microsoft Exchange Information Store service uses the TEMP and TMP folders as temporary storage during various operations, such as message conversion, working with large attachments, and mailbox move operations. 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 Microsoft 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.

On a non-clustered Exchange server, the Exchange store uses the SYSTEM (for example, Local System) folder, which uses a default environment variable setting of %Systemroot%\Temp for both TEMP and TMP. Exchange Virtual Servers that are running in a Microsoft Windows® server cluster use 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.

This article explains how to move the TEMP and TMP directories in clustered and non-clustered environments. Before you perform the procedures in this article, consider the following recommendations:

• 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 recommended that you do not use the disk Exchange transaction logs for the TEMP and TMP folders used.
  
  

To move the TEMP or TMP folders in a non-clustered environment

1. Log on to the computer that is running Exchange Server with an account that has administrative rights.

2. Right-click My Computer, and then select Properties.

3. Select the Advanced tab.

4. Click Environment Variables.

5. In the System variables area, select TEMP and then click Edit.

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

7. In the System variables area, select TMP and then click Edit.

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

9. Click OK to close the Environment Variables dialog box and then click OK to close the System Properties dialog box.

10. Reboot the server to apply all the changes.

To move the TEMP or TMP folders in a clustered environment

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

2. Right-click My Computer, and then select Properties.

3. Select Advanced.

4. Click Environment Variables.

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

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

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

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

9. Click OK to close the Environment Variables dialog box and then click OK 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.

To assign the Authenticated Users group permissions to the TMP or TEMP folders

1. Start Windows Explorer, locate and then right-click the folder that the TEMP variable or the TMP variable points to, and then click Properties.

2. In the Temp Properties dialog box, click the Security tab, and then click Add.

3. In the Select Users, Computers, or Groups dialog box, add the Authenticated Users group to the object names list and click OK.

4. Click Advanced to access advanced security settings.

5. Select Authenticated Users in the Name list and then click Edit to display the Permission Entry dialog box.

6. Use the fields in the Permissions area to allow the following special permissions:

   Traverse Folder / Execute File

   Create Files / Write Data

   Create Folders / Append Data

7. Click OK three times to apply the permissions and exit.

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