Snapshot with memory fails with the error: "Failed to take a memory snapshot, since the virtual machine is configured with independent disks"

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

When attempting to take a snapshot of a powered on virtual machine, the following may appear:

• Unable to take a snapshot with the Snapshot the virtual machine's memory option selected.
• Error: Failed to take a memory snapshot, since the virtual machine is configured with independent disks.

Notes:

• This issue may also appear with RDMs in the physical compatibility mode, because they are always independent. For more information about Raw Device Mapping, see RDM Considerations and Limitations
• Same symptoms appear when attempting to take a snapshot of a suspended virtual machine.

Cause

Taking a virtual memory snapshot allows a virtual machine to be reverted to the state it was when the snapshot was taken. This is achieved by saving the memory state of that virtual machine while taking the disk snapshot. By doing this, a user can revert the original virtual machine functioning state by reloading the memory state and dropping the matching disk snapshot.

 

However, the persistent attribute of a disk prevents the system from taking a disk snapshot, which means that there is no way to revert to the state the virtual machine was in when the snapshot was taken.

Resolution

This is an expected behavior. Virtual machines with independent disks cannot use memory or quiesced snapshots.

 

To resolve this issue, use one of these options:

• When taking a snapshot of a virtual machine, deselect the Snapshot the virtual machine's memory and Quiesce Snapshot options.
• Change the disk mode from Independent to Dependent.
  
  To change the options for the virtual disk(s):
   
  1. Power off the virtual machine
  2. Right-click the virtual machine and click Edit Settings.
  3. Find the affected virtual disk(s) and expand to see all the hard disk details
  4. Change the Disk Mode to Dependent
  5. Click OK to apply and save the changes to the virtual machine configuration.
  6. Now snapshot with memory or quiesced snapshot will complete successfully

Additional Information

For more information on Independent virtual disks and virtual disk provisioning policies, see:

• The Change Disk Mode to Exclude Virtual Disks from Snapshots, see Change Disk Mode to Exclude Virtual Disks from Snapshots
• The Virtual Disk Provisioning Policies, , see About Virtual Disk Provisioning Policies