1. First Take snapshot and Clone of vCenter
2. Take Full back of vCenter VM vi backup tool if using
3. Take snapshot of VMware update manager if using
Upgrade sequence of vCenter from 6.0U1b to 6.5.0 U3f
Ref: VMware VMware Product Interoperability Matrices https://www.vmware.com/resources/compatibility/sim/interop_matrix.php#upgrade&solution=2
1. First need to upgrade the intermeddiate hops from 6.0U1 to 6.U3.
2. Upgrade vCenter from 6.0 U3 to 6.5U1
3. upgrade vCenter 6.5U1 to 6.5U3F ( need intermediate hops) Ref: vSphere Back-in-time release upgrade restriction https://kb.vmware.com/s/article/67077
4. If using VMware update manager on exteranl server then update it.
5. Download vCenter Appliance 7.0
6. run the installer and choose migrate option for migration. (Follow the Wizard)
7. Run migration assistance ( vCenter Migration Assistant. The procedure to run the migration-assistant is the same whether you are trying to upgrade an external SSO, PSC,or Update Manager or an embedded version of these. The migration-assistant should be run on the machines hosting these services separately, before initiating the vCenter Migration/Upgrade. The migration/upgrade process will migrate data from all the components server with an active migration-assistant session.)
7. Need 1 temperory IP for vCenter migration ( IP should be in same subnet as current vCenter)
Note: During migration new vCenter will be deploy and copy the data's from source VC to target VC and vCenter will be powered off during migration. Don't worry about. If any case migration failed no worries exitng vCenter will be there to bring it up without any issue.
ESXi Upgrade from 6.0 to 6.5 and then 7.0
1. Upgrade ESXi 6.0 t0 6.5 Ref: VMware VMware Product Interoperability https://www.vmware.com/resources/compatibility/sim/interop_matrix.php#upgrade&solution=1
2. VMware Tools and VMware hardware on each VMs ( need reboot)
Cautious:Highly recommended to check the VMware Compatibility matrix before upgrade. VMware Product Interoperability Matrices