Virtual Machine Performance Problems
search cancel

Virtual Machine Performance Problems

book

Article ID: 324692

calendar_today

Updated On:

Products

VMware Desktop Hypervisor

Issue/Introduction

My virtual machine runs too slowly. What can I look for to help speed things up?

Resolution

There should be minimal overhead in running a guest operating system in a virtual machine. (Note that there is additional overhead in beta distributions because the software is compiled to aid debugging and is not fully optimized for speed.) For optimal performance, make sure you are using the latest released version. If your virtual machine is too slow to be usable check the following.
Did you install VMware Tools in the guest operating system?

If not, do so. The VMware Tools package includes a display driver that has been optimized for the guest operating system running within a virtual machine. If this optimized driver is not installed, the guest operating system will fall back to using a standard VGA device driver that is completely emulated in software and display performance will suffer dramatically.

VMware Tools packages for many Windows, Linux, and UNIX guests are included with Workstation. To see a full list and find instructions for installing VMware Tools on your guest operating system, see the Guest Operating System Installation Guide.

Did you assign too much memory to the virtual machine and leave none for the host?
It is possible to starve the host operating system so it doesn't have enough memory to operate efficiently by increasing the amount of memory reserved to run virtual machines above the recommended setting. In the Workstation menu, go to Edit > Preferences > Memory to see these settings.
If free memory falls below the minimum necessary value (specific to each host computer's configuration), the host operating system will continually free up memory by swapping to disk to maintain that amount of free memory; this in turn causes the virtual machine to run slowly as well. When reserving memory for a virtual machine, you must leave enough memory for the host operating system to operate efficiently.
Are you running in full screen mode or in a window?
You get the best display performance when the virtual machine takes over the full screen. To switch to full screen mode, click the Full Screen button on the Workstation toolbar.
Are you using DMA for access to IDE drives on host and guest?
For details on making these settings, see the Performance Tuning section of the Workstation manual.
Does the virtual machine intermittently halt or become unresponsive?

If you are not getting a significant fraction of the host processor, check the following:
  • Your host may have CD-ROM autoplay enabled. You should disable that functionality.

  • Your host system configuration may be underpowered. For example, you may not have enough memory to run all the applications and virtual machines you want to run concurrently.

  • Your virtual machine's disk files and any associated files such as redo logs may be mounted on a networked file system. Try running your virtual machine with all the data files stored on local file systems and with no other CPU-consuming applications running. You may also want to reduce the memory size for your virtual machines or add more physical memory to the host machine.
Is there a virtual machine running DOS or some other operating system that idles poorly?

See the DOS idle notes in the Guest Operating System Installation Guide.
Is an ActiveX desktop used inside a virtual machine running Windows 95 or Windows 98?
Are you using animated effects in a Windows guest operating system?

To increase responsiveness from your Windows guest operating system, disable animated windows, menus and lists by unchecking the option from the Effects tab of the Display Properties dialog.
Are you using an unsupported guest operating system?

See Supported and Unsupported Guest Operating Systems in the Workstation manual for a list of supported operating systems.

Unsupported operating systems may run very slowly, if they run at all.

Are your virtual machines using host-only or NAT networking and on a Windows host?

Networking performance on your host may slow down when browsing your Windows host and network. VMware Workstation's virtual networking installs two virtual Ethernet interfaces on the host so that your host can access the host-only and NAT virtual networks, which in turn allow your host to access the virtual machines running on those networks and allows those virtual machines to access the host. If you are already connected to a network, you may notice that it takes a little longer to find all the machines on your physical network because the host checks the virtual networks for any virtual machines that may be running.

If your virtual machines are not using NAT or host-only networking or are not running at the moment, you can disable the virtual network adapters to improve your host's networking and browsing capabilities. Steps follow for each supported Windows host.

Disabling the Virtual Network Interfaces on a Windows 7 Host

1. Open the Control Panel and double-click Network and Sharing Center.
2. Click on Change Adapter Settings.
3. Right-click the host-only adapter and choose Properties.
4. Click Configure.
5. In the Device Usage list, select Disable from this HW profile.
7. Repeat these steps for the NAT adapter.
8. Click OK twice to exit the dialogs.


Disabling the Virtual Network Interfaces on a Windows XP Host
  1. Open the Control Panel and double-click Network and Dial-up Settings.
  2. Right-click the host-only adapter and choose Properties.
  3. Click Configure.
  4. In the Device Usage list, select Disable from this HW profile.
  5. Repeat these steps for the NAT adapter.
  6. Click OK twice to exit the dialogs.

Disabling the Virtual Network Interfaces on a Windows 2000 Host

  1. Open the Control Panel and double-click Network and Dial-up settings.
  2. Right-click the host-only adapter and choose Disable.
  3. Right-click the NAT adapter and choose Disable.

Disabling the Virtual Network Interfaces on a Windows NT Host

  1. Open the Control Panel and double-click Network.
  2. Click the Bindings tab.
  3. Click All adapters.
  4. Check the host-only and NAT adapters, then click Disable.
  5. Click OK to exit.

Additional Information

For translated versions of this article, see:
Powered by Wolken Software