Verifying host networking speed

Products

• VMware
• VMware Desktop Hypervisor

Issue/Introduction

This articles assists you in determining if a computer running a VMware hosted product is affected by slow networking. Slow host networking results in slow guest operating system networking.

Symptoms:

• Applications running in virtual machines perform poorly
• It takes a long time to log into a network
• It takes a long time to copy a file from a network share
• Multi-user services have long transaction times or can handle less simultaneous users than expected

Resolution

Evaluate these points for validity. A positive result may indicate a networking problem on the physical host that needs to be corrected to ensure optimum virtual machine performance.

If corrective action is taken on the host, test virtual machine networking performance again.

• It takes longer to copy a file from a network location to this host than it does to copy the same file to a different host
• Logging into a network from the host takes the same amount of time as it does when logging into the same network from the guest operating system
• There are multiple virtual machines running on the host and they are all equally slow
• Running an application that is slow when run from the guest operating system is just as slow when run on the host
• The networking settings of host network adapters have been manually set to a speed or duplex lower than their capability
• The firmware and driver versions for host network adapters are not current
• There is a firewall, network shaping software, or network monitoring software on the host affecting network speed
• There is software running on the host that makes extensive use of networking traffic, like a heavily used Web server or file share

Consult your vendor documentation for more information about performing these actions.

Additional Information

For related troubleshooting information, see Troubleshooting virtual machine performance issues (1008360).