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Virtual machine becomes unresponsive or inactive when taking a snapshot (1013163)

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If you take a snapshot of a virtual machine with memory, you may experience these symptoms while the memory is being written to disk:
  • The virtual machine becomes unresponsive or inactive.
  • The virtual machine does not respond to any commands.
  • You cannot ping the virtual machine.


This is an expected behavior in ESXi.

For example:

If you take a snapshot of a virtual machine with 4 GB of RAM in ESX 3.x, you see similar entries in the vmware.log file:

Jun 11 09:54:14.626: vmx| Starting save of VM memory to checkpoint file

Jun 11 09:55:20.105: vmx| Done saving memory

This process takes approximately 64 seconds, during which the virtual machine goes through the Fast Suspend Resume (FSR) process and the guest operating system is unresponsive. Time taken by a virtual machine in the FSR state is dependent on the memory to be written to disk for such an operation, and the speed and responsiveness of the datastore's backing storage.

This process has been significantly improved in ESX/ESXi 4.0 Update 1 and later where the FSR time is much shorter.

When the memory is completely written on the disk, the virtual machine resumes normal operation.


vm stun, FSR, stunned, vm unresponsive

See Also

Update History

05/23/2013 - Added tags and used FSR instead of stun.

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  • 38 Ratings