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The File Access Manager driver (FAMv4.sys) is installed

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2009-04-08

On computers that are running Microsoft Exchange Server 2003, the Microsoft Exchange Analyzer Tool parses the list of running services. If the third-party File Access Manager service (FAMv4.sys) is running, the tool generates the following warning message:

Software application <ProgramName> is installed on Exchange server <ServerName> and the service FAMv4 is running. This may cause Exchange ActiveSync or Entourage client failures.

On an Exchange server that is running the FAMv4.sys driver, you may experience the following issue. When Microsoft Entourage users or Exchange ActiveSync users put many items into one of their mailbox folders, such as the Inbox, Calendar, or Contacts folder, they may experience synchronization errors, or they may be unable to access the folder or folders from the client program.

The File Access Manager service is a third-party program that can be used to back up open files. When clients try to access mailbox data for Exchange ActiveSync or Entourage, the following process occurs:

  1. Exchange ActiveSync and Entourage clients request the mailbox data from Internet Information Services (IIS) by using the Distributed Authoring and Versioning (DAV) extensions to the HTTP protocol.

  2. DAV requests the mailbox data from the information store. If many items are requested, the Store.exe process uses a stream file to package the items.

  3. DAV reads from the stream file to return the mailbox data to the Exchange ActiveSync or Entourage client. To read from this file, DAV uses the ReadFile() method.

If a third-party kernel driver, such as the File Access Manager driver, intercepts calls to the ReadFile() method, incorrect data may be returned to Exchange. This behavior causes the Read thread to enter an unending PENDING state. Therefore, the Entourage or Exchange ActiveSync client program may experience poor performance or time-out errors when the program accesses the mailbox data.

To address this issue, contact the program vendor to obtain an updated copy of the File Access Manager service. Or, to work around this issue, disable or remove the File Access Manager driver temporarily.

To disable the File Access Manager service in Windows

  1. Click Start, click Run, type regedit, and then click OK.

  2. In Registry Editor, locate the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\FAMv4

  3. In the details pane, right-click Start, and then click Modify.

  4. In the Value data box, type 4, and then click OK.

  5. Exit Registry Editor.

  6. Click Start, click Run, type cmd, and then click OK.

  7. At the command prompt, type net stop famv4, and then press ENTER.

  8. Verify that Entourage and Exchange ActiveSync clients can synchronize with Exchange successfully.