virtualbox.org

Hi,

I am installing my a Windows XP SP3 guest on a Linux host. The guest will contain apps that are both network and disk intensive.

Are some of the VBOX network or HDD interfaces faster than others? What other tuning can I do to the VBOX setup to optimize for these tasks?

Thanks!

Trevor

The following is based on what I understand to be correct, rather than direct experience.

For network:

• Likely use Bridged networking, because NAT networking introduces a virtual router between the VM and the host's network, which may slow things down.
  (Although the NAT networking TCP buffers and such can be tweaked, see section 9.14, 9.14.3 of the user manual.)
• The VirtIO network drivers work on Windows, which bypass any need to emulate a virtual network card (VirtualBox 3.1.2+).
  http://www.linux-kvm.com/content/tip-ho ... rk-drivers
• Tune the XP TCP/IP stack the same as for a physical PC (it needs tuning out-of-the-box).

For disk:

• Consider a fixed VDI file (not dynamic) and make sure it is contiguous in the host filesystem.
• The virtual SATA drives might go a bit faster than virtual IDE, but install XP on IDE first, then add a SATA controller + Windows drivers then swap the VDI over to the SATA controller seems to be the recommended route.
• Avoid or minimise the use of snapshots.

Thanks, Mark! What network tuning would you suggest? I am aware of tuning and the justification, but I do not know where to begin to determine the numbers to set for the TCP buffers, etc... Do you have any "standard" settings that you use?

m27315 wrote:What network tuning would you suggest?

For tuning internet access on Windows XP, set TcpReceiveWindow (=RWIN) to a bigger value (tweaks to other parameters are likely not needed or are counter productive).
I use DrTCP to set it.
Set it to whatever value your Bandwidth Delay Product suggests you set (this calculation depends upon your bandwidth available, and your under-load round-trip ping delay to sites you use).
The Speed Guide TCP/IP Analyzer can suggest a value for you.
The Speed Guide TCP Optimizer is probably very good, but I have never used it.

For tuning local network access, I have no idea.