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I have Windows 7 32-bit virtual machine running in a VMWare Server virtual machine. The host is Windows 7 64-bit.

When I copy files between them it is extremely slow - it will take several minutes to copy even a 1 MB file. I can upload the file to an website and then download it again almost instantaneously by comparison.

Browsing the network is quite zippy and has no problems. I have been unable to set up a HomeGroup between the computers though - the guest always times out without managing to get setup.

Any ideas on how I should go about tracking down where the problem is?

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up vote 5 down vote accepted

I've been searching for this myself on the forums. And I've eventually found the solution on VMWare's KB here

Basically it tells you to disable TCP Offloading which means your host/guest traffic is actually being sent to the NIC when all you need is for it to stay local.

My NIC driver under device manager also had additional Offload options such as checksum offloading.. I've disabled these too...

My file xfer speed between Host to Guest has now gone from 30kb/s to 50MB/s ... much better! :) Just posting it here for the benefit of future googlers...

p.s. in my case, the new settings took effect without a reboot... the NIC reset itself after changes to the driver, I've also done an ipconfig /renew on the guest.. neither host nor guest were down for this.


keywords: slow vmware server network traffic copy file guest host tcp ip LAN SMB UNC shared folders

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Thank you very much! – garethm Mar 16 '10 at 11:25
This question and answer was driving me crazy since a week now. Thank you very much! :D – FlyBy Jan 16 '13 at 13:13

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