Hi - I am currently running VDP 5.1 on an old ESXi 5.1 host.
I have bought a new ESXi host running 5.1 U1
I would like to upgrade to VDP 5.5.1 but would rather install a fresh copy of VDP 5.5.1 on the new server and not upgrade or move the old VDP 5.1
However... I would like to keep the old VDP 5.1 just in case I ever need to go back to it for some unforeseen reason (highly unlikely). I don't mind starting a fresh backup routine/database with the new 5.5.1.
How can I uninstall 5.1 from my vCenter 5.1 U1 server without deleting the existing backups and then install a fresh VDP 5.5.1 with a brand new database?
The following KB explains how to uninstall VDP but its deletes all the backup data ( VMware KB: Uninstalling vSphere Data Protection from vCenter Server )
How Can I remove VDP from vCenter without actually deleting the data and then also install VDP 5.5 on the same vCenter but to an new ESXi host?
The KB you referenced is what you want. That will simply remove the VDP Plugin from the vSphere web client and the vCenter.
The appliance will still exist and the backup jobs and restore points will still exist.
If you remove the plugin, then deploy the vDP 5.5.1 appliance, then you will see a VDP 5.5 plugin in the vSphere web client.
This plugin will see your old VDP 5.1, but the new UI functionality will not function with the VDP 5.1 appliance.
Assuming that the ESXi hosts are both associated to the same vCenter.