This issue can occur when the Exchange anti-virus API is in use, because each message that contains an attachment must be scanned before it is released to a client by the Exchange Server Information Store. If the scanning queue contains messages that contain many attachments or several large attachments, the client may time out while it waits for the server to release the message that contains the attachment.


Solution 1:

Change the scan options on the anti-virus software that is using the Exchange anti-virus API to "MAPI" instead of "MAPI/AVAPI." This should increase the transfer rate significantly, and eliminate "Drive Not Responding" errors during mailbox backups. Instructions for adjusting this setting will vary from one anti-virus software package to another.

Solution 2:

To disable the anti-virus API for the Exchange Server using the registry editor, follow the steps given below:

1. Start the registry editor (Regedt32.exe)

2. Locate the Enabled value under the following key in the registry:

NOTE: If the VirusScan registry key is not present, then the antivirus API is not in use or has not been enabled on the Exchange Server.

3. Select Edit | DWORD, and then type 0 and click OK

4. Quit the registry editor

Solution 3:

Add or change the OpenRetryDelay value in the registry to try to resolve this issue. This value is the time interval in milliseconds that the information store pauses before it attempts to reopen attachments that are currently being scanned, when those attachments are requested by the client. If this value is set too high, this may cause client time-outs, and if this value is too low, it may cause additional processing overhead by the Information Store. If this value is not present in the registry when the anti-virus API is in use, it has a hard-coded default value of 500 milliseconds.

1. Start the registry editor (Regedt32.exe)

2. Locate the following key in the registry:

If the VirusScan key is not present, the anti-virus API is not in use or has never been enabled on the Exchange Server computer.

3. Locate the OpenRetryDelay value under the preceding key in the registry. If the OpenRetryDelay value is not present, go to step 5.

4. Select Edit | DWORD and type 2500, change to Radix from Decimal, and then click OK

5. If the OpenRetryDelay value is not present, add it. On the Edit menu, click Add Value, and then add the following registry value:

Value Name: OpenRetryDelay

Data Type: REG_DWORD

Radix: Decimal

Value: 2500

6. Quit the registry editor

7. Stop and restart the Information Store service (Control Panel | Services for Windows NT 4.0 or Control Panel | Administrative Tools | Services for Windows 2000) to allow the changes to take effect.

Note: In the NAVMSE 2.18, the user interface is used to change the value for the Exchange client retry delay to lower the delay. The Exchange client retry delay is found when you select Autoprotect | Scan | VAPI/MAPI.

Note:  It is recommend by VERITAS Software to contact the virus protection vendor for the latest methods to enable or disable modes. In some cases, batch files may be provided as a method of switching between modes.

Note:  Symantec recommends that customers experiencing the issues mentioned in this document upgrade to the latest versions of each of the products used to ensure the highest levels of compatibility between them. Please contact your sales representative or reseller to obtain upgrade information for your products. Additionally, you may also contact Symantec Sales directly at    http://www.symantec.com/purchase/ and http://www.veritas.com/buy/BuyHome.jhtml