We have f5 VMs hosted in Azure and we want to upgrade these VMs. We are thinnking to spin a new VM with version 15.1.x and upload the backup of existing VMs which are running on 18.104.22.168. Devices are in Active/Active.
Has anyone upgarded their devices by this method, please share your experience how feasible it is and also share steps and documents how to proceed with this approach.
it can be a little bit tough, but it's technically possible.
I recommend you to check this first.
There are a lot of changes between v12.1 and v15.1, especially in the security modules.
Remember that when you plan for an upgrade to BIG-IP 15.x, F5 recommends that you must be running BIG-IP 13.x through 15.x to upgrade to BIG-IP 15.x.
K13845: Overview of supported BIG-IP upgrade paths and an upgrade planning reference
A better approach could be upgrade from v12.1 to v13.1 and then try the platform-migrate option to go to v15.1.
K82540512: Overview of the UCS archive 'platform-migrate' option
My 2 cents.