As part of an SRM project, we are upgrading a customer's production-site vCenter server. This vCenter has four ESXi 5.5 hosts with a mix of servers and desktops in a XenDesktop 7.1 environment. There are about 100 desktops, all with Personal vDisk and some user/application-specific customizations based on the customer's business requirements.
To reduce the downtime and risk of the vCenter upgrade, we elected to build a new VCSA 5.5U2b server to replace the existing vCenter server. (We will actually keep the server, and install SRM 5.8 on it as well as retain the Update Manager installation that's on that box). I plan to swing the existing hosts from the Windows vCenter 5.5U1 server to the new VCSA 5.5U2b server. I had planned to just re-point the XenDesktop Delivery Controllers to the new vCenter Server hostname, but it seems from some discussions I've seen that this approach may not work because the VCSA and its various objects (Data Center, Clusters) will have different GUIDs. Re-creating the desktops would be a significant undertaking; all of the desktops have to be configured for the app customizations after a user logs in. This approach is contrary to our goals of minimizing downtime and risk.
I'm seeking any tips or guidance on how to go about this migration with minimal risk to the XenDesktop environment, since that's highly critical to the customer's business. One of the secondary goals here is to unload the vCenter services from the original vCenter server and use it just for SRM and Update Manager; adding the new VCSA lets us split up the workloads.
Thanks in advance for any guidance.