Common VMware Mistake: How to Re-Register a Virtual Machine in vCenter

Everyone knows how to move, clone or copy a virtual machine using the vSphere wizard. In this quick example, I am going over a feature that is extremely useful and annoyingly hidden in the vSphere Web Client– how to register a virtual machine.

What’s the difference? This workflow is almost exclusively used in backups.

In my scenario, a VM failed and customer requested a restore from one of the snapshots in the Storage Area Network in a different location. Ordinarily this is not a process you encounter often as the first choice should be restoring from a backup, which hopefully you have integrated in your vCenter, so it only requires a few clicks.

This system was not yet in production, so a backup solution was not in place. Thus, we needed to do a little extra work.

Here is the workflow I went through to restore from a snapshot and re-register the same VM into vCenter:

1. Clone the snapshot on the SAN
2. Create a Volume from new clone
3. Setup iSCSI permission on the volume in SAN GUI
4. Mount new volume via iSCSI to vCenter as new datastore
5. Finally, re-register the VM as a new one

The entire motivation to write this post came from the fact it took me a solid 5 minutes of clicking trying to find where the re-register button is. Take a look: It is in the right click menu of the Datastore browser– not where you’d expect.

To sum up, if you are restoring an existing VM, it is always the best practice to re-register the VM instead of creating a new one from the VMDK file as the registration process will ensure all the settings such as CPU, MEM, SWAP, and others will carry over.

JacobR, PEI