Troubleshooting a Fusion virtual machine that uses 100% of the guest CPU

Products

• VMware Desktop Hypervisor
• VMware Fusion

Issue/Introduction

This article lists the troubleshooting steps to follow when a Fusion virtual machine is using 100% of its own CPU, but the Mac's CPU is relatively unaffected.

Note: For information about troubleshooting a Fusion virtual machine that uses 100% of the Mac's CPU, see Troubleshooting a Fusion virtual machine that uses 100% of the Mac's CPU (328427).

Symptoms:

• A Fusion virtual machine is slow to respond
• The virtual machine is using 100% of its CPU
• Applications on the virtual machine seem frozen or do not respond

Environment

VMware Fusion 2.x
VMware Fusion 4.x
VMware Fusion 5.x
VMware Fusion 7.x
VMware Fusion Pro 8.x
VMware Fusion 10.x
VMware Fusion 8.x
VMware Fusion 3.x
VMware Fusion Pro 10.x
VMware Fusion 6.x

Resolution

Each step below provides instructions and a link to a document for performing the step and taking corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution while minimizing data loss. After completing each step, restart the virtual machine and check if it is more responsive and using less CPU. Each troubleshooting step should be followed in order without skipping any.

Troubleshooting a Fusion Virtual Machine Using 100% of the Guest CPU:

1. Identify any applications or processes that are either using 100% of the CPU or contributing to the total CPU usage reaching 100% when combined with other running applications and processes. For more information, refer to Investigating Operating System CPU Usage (315429).

   Note: Any services with high CPU usage might be the cause of this issue. If possible, disable these services. Performing a web search for the process name often helps identify the associated application. The application can then be prevented from automatically starting or uninstalled if necessary.

2. Verify that sufficient resources from the Mac are allocated to the virtual machine. If less RAM is allocated than what the virtual machine's operating system and applications require, frequent writing of RAM contents to disk may occur, significantly impacting performance. For more information, refer to Investigating Virtual Machine Resources in VMware Fusion (310353).

3. Ensure that AutoProtect is turned off. AutoProtect writes the contents of the virtual machine's RAM to disk as part of its process, which can impact performance.

   To turn off AutoProtect:

   • Fusion 10.x:

     1. In the Fusion menu bar, go to Virtual Machine > Snapshots.

     2. Ensure that the AutoProtect checkbox is unchecked.

   • Fusion 4.x and above:

     1. In the Fusion menu bar, go to Virtual Machine > Snapshots.

     2. Ensure that the AutoProtect switch is set to OFF.

   • Fusion 2.x and 3.x:

     1. In the Fusion menu bar, go to Virtual Machine > Settings.

     2. Click AutoProtect and deselect Enable AutoProtect.

   For more details, refer to the following topics in Fusion Help:

   • Using Snapshots and AutoProtect

   • Set Up Automatic Snapshots with AutoProtect

4. Disconnect any USB devices from the virtual machine.

5. Reboot the Mac.

If the issue persists after completing these steps:

• Collect VMware Support information. For more details, refer to Collecting Diagnostic Information for VMware Fusion (344567).

• File a support request with VMware Support and reference Knowledge Base article ID 344344 in the problem description. For additional guidance, refer to How to Submit a Support Request.