An error occurred while taking a snapshot: Failed to quiesce the virtual machine. ESXi 6.5 - Windows 2012 R2

The Issue

The virtual machine has a physical RDM (Raw Device Map) attached. When taking a backup or manual snapshot, you will see the following error:

"An error occurred while quiescing the virtual machine. See the virtual machine's event log for details."

"An error occurred while taking a snapshot: Failed to quiesce the virtual machine."

"An error occurred while saving the snapshot: Failed to quiesce the virtual machine."

Quiesce Snapshot Failed

Event Viewer Error

An error also appears in the Event Viewer application logs of the system:

Volume Shadow Copy Service error: Unexpected error DeviceIoControl(
\\?\fdc#generic_floppy_drive#6&2bc13940&0&0#{53f5630d-b6bf-11d0-94f2-00a0c91efb8b}
- 00000000000004DC,0x00560000,0000000000000000,0,0000023AEBCEF9B0,4096,[0]).
hr = 0x80070001, Incorrect function.

Operation:
   Exposing Recovered Volumes
   Locating shadow-copy LUNs
   PostSnapshot Event
   Executing Asynchronous Operation

Context:
   Device: \\?\fdc#generic_floppy_drive#6&2bc13940&0&0#{53f5630d-b6bf-11d0-94f2-00a0c91efb8b}
   Examining Detected Volume: Existing - \\?\fdc#generic_floppy_drive#6&2bc13940&0&0#{53f5630d-b6bf-11d0-94f2-00a0c91efb8b}
   Execution Context: Provider
   Provider Name: VMware Snapshot Provider
   Provider Version: 1.0.0
   Provider ID: {564d7761-7265-2056-5353-2050726f7669}
   Current State: DoSnapshotSet

VMware Snapshot Error

Solution

There can be multiple reasons for this error to appear. Below are two methods to resolve it.

Method 1: Remove the Floppy Drive

  1. Right-click the virtual machine and select Settings.
  2. You will find there is a floppy drive listed, which is commonly not required. You can also confirm this by logging on to the operating system and checking the drives in My Computer.
  3. Attempt to remove the floppy drive. You may fail, so you have to shut down the VM and remove it.
  4. In some cases, the floppy drive still appears in My Computer even after removing it from settings. Follow these additional steps to completely get rid of it:
    • Power off the virtual machine.
    • Right-click the virtual machine and click Edit Settings.
    • Click the Options tab.
    • Click Boot Options under Advanced.
    • Select The next time the virtual machine boots, force entry into the BIOS setup screen option.
    • Power on the virtual machine.
    • Using arrow keys, disable Legacy Diskette A:.
    • Press F10 to save the changes and exit. The machine reboots and completes the configuration.

Method 2: Modify VMware Tools VSS Support

  1. Open Programs and Features, right-click VMware Tools, and select Change.
  2. Click Next, then select Modify.
  3. Select Volume Shadow Copy services support, click Entire feature will be unavailable.
  4. Click Next, then click Change, and finally click Finish.

Virtual Machine Snapshot Failed

Frequently Asked Questions

What does "quiesce" mean in VMware snapshots?

Quiescing a virtual machine means pausing or freezing the file system I/O operations using VMware Tools and the guest OS Volume Shadow Copy Service (VSS). This ensures a consistent snapshot of the disk state without data corruption.

Does removing the floppy drive affect the virtual machine?

No. Modern operating systems do not require a floppy drive. Removing it from the VM settings eliminates a legacy device that can interfere with the VSS quiesce process during snapshots.

Will disabling VSS in VMware Tools affect my backups?

Disabling VSS means snapshots will be crash-consistent rather than application-consistent. This is acceptable for most workloads, but database servers (such as SQL Server or Exchange) should use application-consistent snapshots for reliable recovery.

Does this error occur on ESXi versions other than 6.5?

Yes. The "Failed to quiesce" error can occur on any ESXi version when a floppy drive or incompatible device interferes with VSS operations. The same solutions apply to ESXi 6.7, 7.0, and 8.0.

Can I take a snapshot without quiescing?

Yes. When creating a manual snapshot in the vSphere Client, uncheck the "Quiesce guest file system" option. This creates a crash-consistent snapshot that does not invoke VSS, avoiding the error entirely.