On a Dell T410 server running Windows 2008 R2 SP1 we are experiencing slow performance when running applications on a Windows 2008 R2 guest OS that access files on network shares on other non-virtualized servers. I've tried disabling the TCPChecksumOffloadIPv4 and disabled TCP Chimney Offload but this has not improved anything.
The server has a RAID 1 configuration and the VHD is a fixed size.

asked 12/01/2011 10:04

jtforde518's gravatar image

jtforde518 ♦♦

7 Answers:
I would look at your RAID 1 datastore, if the VHD is stored on this RAID array. RAID 1 is very poor for read and write performance.


hanccocka's gravatar image


Set this:

Key: HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Value(DWORD): DisableTaskOffload = 1


answered 2011-12-02 at 06:26:36

Govvy's gravatar image


Do you have a Westmere or Sandy Bridge processor? If you do, there is a hot fix for you.

answered 2011-12-02 at 07:16:13

kevinhsieh's gravatar image


If they are W7 puters then even configured within a home group, they have a pass phrase to access shares on that workgroup... It's a shared secret..

W7 also offers password protected sharing with 128 bit encryption..

Here is a list of options and how to set it up:

answered 2011-12-02 at 08:26:06

ChiefIT's gravatar image


@ChiefIT, did you post to the wrong thread?

answered 2011-12-03 at 14:48:40

kevinhsieh's gravatar image


LOL, I sure did:

Lost the other thread that this comment was intended for, too. Sorry about that folks..

answered 2011-12-03 at 14:51:20

ChiefIT's gravatar image


While applying the hotfix kevinhsieh mentioned and disabling the task offload for the NIC in the registry improved file access and file copy from VM to physical server shares and to VM from physical server shares I'm still experiencing a slowdown in running a tool that opens reads PDF files to process information they contain. We are modifying this tool to provide debug info to further troubleshoot. This tool works fine when running from a physical server running Win2K3 to another physical Win2K3 server where the PDF files are stored but when we run it from the virtual server to the physical share it's incredibly slow.

answered 2011-12-03 at 15:26:06

jtforde518's gravatar image


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Asked: 12/01/2011 10:04

Seen: 469 times

Last updated: 12/08/2011 05:59