Troubleshooting disk snapshots


This page shows you how to resolve issues with disk snapshots.

VSS snapshot errors

This section lists issues that you might encounter when backing up your disks with Windows VSS snapshots, and provides suggestions for how to fix them.

VSS snapshot failed

If you attempt to create a VSS snapshot of a disk while running an outdated version of the guest environment, you might encounter the following error:

Guest Consistent Snapshot failed (Detail: Failure within guest).
Verify you are running the latest image version and agent.

To resolve this, install the latest version of the guest environment and then reattempt to create the snapshot.

Failure to boot VM after creating VSS snapshot of a boot disk

When you create a VSS snapshot, Windows Server marks the source disk as read-only. When you create a new persistent disk from the VSS snapshot, that disk is also set to read-only mode, which might cause issues.

For example, if you create a VM instance with a new boot disk that is based on a VSS snapshot of a boot disk, the read-only flag on the new boot disk prevents the VM instance from booting correctly. In this scenario, the VM might fail to boot with the following errors:

  • Failed to open disk
    
  • Status: 0xC0000225 Info: The boot selection failed because a required device is inaccessible.
    
  • ERROR: (gcloud.beta.compute.instances.create) Could not fetch resource:
     - Internal error. Please try again or contact Google Support.
    
  • No startup scripts to run.
    

To resolve these errors, remove the read-only flag from any new disk that you create from a VSS snapshot. For more information, see Marking your disk as available for read and write.

Snapshot frequency errors

This section lists issues that you might encounter when creating frequent disk snapshots and provides suggestions for how to fix them.

Creating snapshots from persistent disks

If you try to snapshot your disk more than 6 times in 60 minutes, you see the following error:

If the limit is exceeded, the operation fails and returns the following error:

"code": "RESOURCE_OPERATION_RATE_EXCEEDED",
"message": "Operation rate exceeded for resource 'projects/project-id/zones/zone-id/disks/disk-name'. Too frequent operations from the source resource."

To resolve this issue, take a snapshot of the disk at most once per hour as a best practice. Avoid taking snapshots more often than that. The easiest way to achieve this is to set up a snapshot schedule. For more information, see Best practices for creating snapshots from persistent disks.

Creating new zonal persistent disks from snapshots

If you try to create a new zonal persistent disk from the same snapshot in the same zone, more than once in 10 minutes, you see the following error:

"code": "RESOURCE_OPERATION_RATE_EXCEEDED",
"message": "Operation rate exceeded for resource 'projects/project-id/zones/zone-id/disks/disk-name'. Too frequent operations from the source resource."

To resolve this issue, create an image from the snapshot instead of repeatedly restoring the snapshot in the same zone to create many persistent disks.

Then, use the image to create new disks. For more information, see Best practices for creating new zonal persistent disks from snapshots.