Users cannot copy files from a network share when OfficeScan client is installed. The machine only goes back to normal when the OfficeScan client TmTDI is disabled or is using a PassThru drive.
The computer stalls when:
- Copying files from a mapped network drive or via UNC
- Viewing the directories via command prompt using "dir"
Microsoft has identified that when you start to copy files from the remote server, the upper level OS components (explorer.exe components) send the I/O requests to the underlying drivers (mrxsmb.sys and rdbss.sys) to perform real tasks. When the process is in progress, the drivers use an I/O request packet (IRP) to pass the information forward and back.
After the kernel mode drivers got the I/O requests and started to process the file copying, the explorer.exe component starts to wait for this operation to finish. However, later it will turn out that the explorer.exe program never gets the I/O completion notification and just gets into an infinite waiting state, causing the whole process to be unfinished.
Further investigation revealed that the thread that was performing the real file I/O was already terminated and all the I/O operations were finished. When the Trend Micro software runs on the server, its drivers also have a chance to touch the I/O request packets related to network file accessing and network packets transmission.
To resolve this issue:
- Open a command prompt (run as administrator).
- Enter this command:
"netsh int tcp set global chimney=disabled"TCP chimney offloads CPU resource to network interface card to improve system performance. This feature requires the NIC driver support to function. You may refer to the Microsoft article for more information: Information about the TCP Chimney Offload, Receive Side Scaling, and Network Direct Memory Access features in Windows Server 2008.
The current TDI architecture used in Vista and above platforms may have caused the problem, but NSC PDG will be replacing TmTDI to better work with the new operating systems.