- Published on
Slow Network Speed on Ubuntu Running in VMware
- Authors
- Name
- Daisuke Kobayashi
- https://twitter.com
The other day I switched from VirtualBox to VMware because USB recognition was not working well in VirtualBox. This is a note from that migration.
Environment:
- VMware Player 4.0.4
- Host OS: Windows XP 32bit Professional Edition
- Guest OS: Ubuntu 12.04
After installing Ubuntu and running updates, I noticed that the network speed was strangely slow. In a fiber connection over wireless LAN, I think I was only getting around 200 - 300 [Kbyte].
After digging into it, it seems that a network card feature called TSO (TCP Segmentation Offload) was causing the trouble. TSO offloads some TCP-related processing that would normally be done by the CPU onto hardware in order to reduce CPU load and improve performance.
Some of VMware's networking behavior appears to depend on the host OS, and that seems to have interacted badly here. Editing the Windows-side registry fixed it.
Open [Start Menu] -> [Run] -> [regedit], then set DisableTaskOffload to 1 as a REG_DWORD under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.
Reference:
http://www.ginnokagi.com/2008/05/vmwaretcp_segmentaion_offload.html