Resolving Veeam Proxy VM Storage Migration Error

Comprehensive Guide to Fixing Non-Persistent Disk Issues in Virtual Machines

Key Takeaways

Identify and Change Disk Mode: Ensure that all virtual disks, especially secondary ones, are set to persistent mode.
Backup Before Modifications: Always create backups or snapshots to prevent data loss during configuration changes.
Validate Configuration Post-Fix: After making changes, verify the VM’s settings and perform test migrations to confirm resolution.

Understanding the Error

The error message "Virtual machine is configured to use a device that prevents the operation: Device 'Hard disk 2' is disk which is not in persistent mode" indicates that the secondary hard disk of your virtual machine (VM) is set to non-persistent mode. In this configuration, any data written to the disk is discarded when the VM is powered off, which poses a risk during migration processes like those performed by Veeam Backup & Replication.

Causes of the Error

Several factors can lead to this error:

Non-Persistent Disk Configuration: The secondary disk is intentionally or accidentally set to non-persistent mode, preventing data retention after shutdown.
Snapshot Dependencies: Existing snapshots may enforce a non-persistent state on certain disks.
Configuration Missteps: During VM setup or modification, incorrect disk mode settings can lead to this issue.

Step-by-Step Guide to Fix the Issue

1. Preliminary Checks

Before making any changes, perform the following checks:

Backup the VM: Take a full backup or snapshot of the VM to prevent data loss.
Identify the Virtualization Platform: Determine whether you are using VMware vSphere, Microsoft Hyper-V, or another platform, as steps may vary slightly.
Verify Disk Usage: Ensure that 'Hard disk 2' is not actively used by critical applications before proceeding.

2. Power Off the Virtual Machine

To safely modify disk settings, power off the VM:

Access your virtualization management console (e.g., VMware vSphere Client).
Locate the problematic VM.
Right-click the VM and select Power Off.

3. Change Disk Mode to Persistent

Modify the disk settings to switch from non-persistent to persistent mode:

For VMware vSphere

Open the vSphere Client and navigate to the VM in question.
Right-click the VM and select Edit Settings.
In the Virtual Hardware tab, locate Hard disk 2.
Click on the disk to expand its settings.
Find the Disk Mode option and change it from Non-persistent to Persistent.
Click OK to save the changes.

For Microsoft Hyper-V

Open the Hyper-V Manager and select the VM.
Right-click the VM and choose Settings.
Under Hardware, select Hard Drive 2.
Click on Inspect to view disk details.
Change the disk mode to Persistent.
Save the settings by clicking Apply and then OK.

4. Validate the Changes

Ensure that the disk mode has been successfully updated:

Re-open the VM settings.
Confirm that Hard disk 2 is now set to Persistent.
Check for any error messages or warnings.

5. Power On the Virtual Machine

Start the VM to apply the changes:

Right-click the VM and select Power On.
Monitor the VM to ensure it boots correctly without errors.

6. Retry the Veeam Migration

With the disk mode now set to persistent, attempt the migration process again:

Open the Veeam Backup & Replication console.
Initiate the storage migration task for the VM.
Monitor the task for successful completion.

7. Post-Migration Verification

After a successful migration, perform the following:

Ensure all data on Hard disk 2 is intact and accessible.
Confirm that the VM operates as expected in the new storage location.
If necessary, revert Hard disk 2 back to non-persistent mode using the same steps outlined above.

Additional Considerations

Backup and Data Integrity

Always perform a full backup or snapshot of your VM before making any configuration changes. This ensures that you can restore the VM to its previous state in case of unforeseen issues.

Impact on Linked VMs

If Hard disk 2 is shared among multiple VMs (e.g., via a shared VMDK), changing its mode to persistent may affect other VMs. Ensure that such configurations are accounted for to prevent disruption.

Testing in a Controlled Environment

Before applying changes to production VMs, consider testing the process on non-critical VMs or in a lab environment. This helps identify potential issues without risking important data.

Reviewing Logs for Deeper Analysis

If the error persists after following the steps, examine the relevant logs for more detailed error information:

VMware Logs: Check the vSphere logs for any disk-related warnings or errors.
Veeam Logs: Access Veeam's support information to review logs that may provide further insights.

Alternative Solutions

If changing the disk mode is not feasible due to specific operational requirements, consider the following alternatives:

Create a New Persistent Disk: Add a new persistent disk to the VM and migrate data from the non-persistent disk.
Modify Workflow: Adjust the VM's operations to eliminate the need for a non-persistent disk during migration.

Conclusion

The error "Virtual machine is configured to use a device that prevents the operation: Device 'Hard disk 2' is disk which is not in persistent mode" can hinder critical migration tasks in Veeam Backup & Replication. By methodically changing the disk mode from non-persistent to persistent, verifying configurations, and ensuring data integrity through backups and testing, this issue can be effectively resolved. Always prioritize maintaining the stability and reliability of your virtual environments by following best practices during such operations.