Starting with version 4.5, you can upgrade the vCloud Usage Meter appliance by using an .iso image that includes a complete Photon OS update.
If you migrate from vCloud Usage Meter 3.6.x, you must accept the legal agreement that is displayed after you complete the migration to vCloud Usage Meter 4.5.
If you want to run in parallel both old and new appliances for a full reporting period, in Commerce Portal, set the vCloud Usage Meter 4.5 instance to Test mode. The product consumption data from the vCloud Usage Meter 4.5 instances is still collected, aggregated, and made available for reference to you. For more infomration, see the https://kb.vmware.com/s/article/82529?lang=en_US KB.
Then if you want to enable vCloud Usage Meter 4.5 for reporting, in Commerce Portal, update the mode of the vCloud Usage Meter 4.5 instance from Test to Production, and shut down and back up the vCloud Usage Meter 3.6.x appliance. You must keep the back up from the vCloud Usage Meter 3.6.x instance for 36 months.
Partner Connect Program stipulates that Service Providers keep the product consumption data for 36 months going back from the current month.
To upgrade the vCloud Usage Meter appliance, you must install only the official vCloud Usage Meter updates provided by VMware.