Storm season is back, bringing with it the potential for significant weather events. If you have clients in areas prone to infrastructure disruption, visit the Disaster Recovery Resources guide for preparedness information. Datto recommends performing proactive disaster recovery testing to mitigate potential downtime. See our articles about the importance of disaster recovery testing and Preparing For A Cloud Virtualization Test: Policies, Procedures, And Partner Responsibilities to learn more. For live updates, follow @datto on Twitter.

Restoring A Thin-Provisioned Image Export To VMware ESXi with VMware Converter & vmfkstools



This article describes the steps to restore a thin-provisioned VMDK image export to a VMware vSphere environment. Two conversion methods are provided: VMware Converter & vmfkstools (VMware command line).

Use the VMDK / VMDK-linked export method if you need to copy the image export as thick-provisioned. 


  • Datto ALTO
  • Datto SIRIS
  • VMware Converter
  • vmfkstools


To export a thin-provisioned disk image for use on VMware ESXi host:

1. Access the Datto appliance GUI.

2. Click the Restore tab.

3. Select the system to restore, and then click Export Image.

4. Choose the recovery point that you want to use, and then click Start Restore.

Figure 1: Start Restore (click to enlarge)

5. Choose the Destination. In Figure 2, the device is sending the restore to a Network Share.

6. Select VMDK as the Format.

  • VMDK-linked image exports are not compatible with VMware Converter, and cannot be used to complete this process.

7. Select the desired boot type: MBR, EFI, or Auto Detect.

Figure 2: Export Image (click to enlarge)

8. Click Export. The Datto appliance will create a clone of the point you selected and share it on the local network.

9. The GUI will refresh with new options. Copy either the Samba or NFS VMDK share path to your clipboard.

Figure 3: CIFS/Samba VMDK share path (click to enlarge)

Select a conversion method to continue:

VMware Converter

1. Launch VMware Converter standalone.

2. Create a new VMX template on your hypervisor for the virtual machine, and attach the .datto files in the network share to the export as disks.

3. Click Convert Machine.

4. Select Powered off, followed by VMware Workstation or other VMware virtual machine as the Source Type, and click Browse.

Figure 4: Source System wizard (click to enlarge)

5. Select the VMX template you created in Step 2.

6. Click Next. Set the Destination Type to VMware Infrastructure Virtual Machine.

7. Enter your server address and server credentials in the VMware Infrastructure server details field. Click Next.

Figure 5: Destination System 

8. In the Name field, enter the VM name that you want to assign to the export and click Next.

9. Choose the datastore in which to house the information.

10. Select the virtual machine version. It is reliant on the version of ESXi that you are converting into. This example uses Version 9. Note that Version 10 is incompatible with the vSphere desktop client.

11. Click Next. Set the Data to copy field to Thin provisioning.

Figure 6: Transfer settings wizard

12. Click Next, and then Finish. The transfer job will start running on your host.

13. When the transfer completes, access your vSphere environment. Make sure that the machine's settings match the needs of your environment. Make any adjustments needed. Then, proceed to the Cleanup section of this article.


To copy the datastore from the Datto appliance to a permanent datastore on VMware with thin disk provisioning, use the following command:

vmkfstools -i /vmfs/volumes/[SourceDataStoreName]/[DriveLetter].vmdk -d thin /vmfs/volumes/[DestinationDataStoreName]/[DriveLetter].vmdk

The SourceDataStoreName is the datastore you created which references the NFS share on the Datto appliance. The DestinationDataStoreName is the datastore on your environment where the disk images will be copied to.


vmkfstools -i /vmfs/volumes/Datastore/C.vmdk -d thin /vmfs/volumes/HostStorage001/C.vmdk

Once the copy completes,proceed to the Cleanup section of this article to continue.


1. When the transfer completes, access your vSphere environment. Create a new virtual machine or attach the transferred disks to an existing virtual machine as necessary.

2. Make sure that the machine's settings match the needs of your environment. Make any adjustments needed.

  • If your import process requires a VMX template, you will need to create one before attaching the virtual disks. The Image Export process does not generate a VMX template.
  • Make sure to attach the boot.vmdk file first, followed by c.vmdk, and then any other applicable drives.

3. Boot the virtual machine. Make sure that it boots to the Windows login screen. If the virtualization fails after the first attempt, try again with a different storage controller. If the issue persists, contact Datto Technical Support.

4. After confirming that the virtual machine functions as expected, return to the Export Image screen in your Datto appliance's GUI, and click Unmount to remove the shared clone.

Figure 7: Unmount image (click to enlarge)

Additional Resources

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