While attempting a vRanger hot-add backup on a VM resident on a vSphere 5 Host, shortly after the remote VM's disks are mounted to the vRanger VM, a hard-crash of the vRanger VM occurs, and the vRanger VM either shows a Windows "Blue Screen", or reboots spontaneously. The Hot-added disks remain mounted to the vRanger VM (after it is accessible after reboot), and must be removed manually. Also, the VM that was being backed up has a snapshot left behind on it from the failed backup that also must be removed manually (via the "Consolidate" feature in vSphere 5). The vSphere client's "Tasks" pane on reboot shows several "Invalid Hardware" messages related to the vRanger VM on reboot as well.
The vRanger VM may be a VMWare Virtual Hardware Version 7 machine, and the VM that was being backed-up via hot-add may be a Virtual Hardware Version 8 machine. The newere .vmdk disks on the newer hardware version cannot be properly hot-added to the "older" version 7 hardware of the vRanger machine, resulting in the hard-crash of the vRanger VM (hardware conflict).
1) Power-off the vRanger VM
2) Right-click the vRanger VM and select "Upgrade Virtual Hardware". This will convert the VM to Virtual Hardware Version 8.
3) Power-on the vRanger VM.
4) Remove any "extra" disks on the vRanger VM that remain (i.e. the one's that were hot-added that still belong to the other VM. Do this via the "Edit Settings" page of the vRanger machine in the vSphere client, and "Remove" any disks that are not local to the vRanger machine itself.
5) Commit the changes.
6) Consolidate any snapshots that remain on the VM that was being backed-up by performing a "Consolidate" operation in the vSphere client.
7) Re-attempt the hot-add backup. It now should proceed normally.
VM Virtual Hardware Versions are usually backward compatible (i.e. Version 8 can enumerate Version 7 Hardware), but not necessarily "forward" compatible (i.e. Version 7 Hardware cannot enumerate/interpret the newer Version 8 Hardware).
