Hello friends,
A doubt some time ago I did a downgrade to version 7 to have several of my servers in 6.5 but I think it's time to upgrade both the vsphere from 6.5 to 7 and vcenter also from 6.5 to 7, I could tell me or help me what would be the procedure to perform, I do not know whether to upgrade first the vcenter or perform the esxi, if you can help me. I would appreciate it.
Regards
The first product to upgrade is vCenter Server, because vCenter Server does not support ESXi hosts with a newer version.
That said, make sure that ESXi 7.0 support your hardware, and don't forget to verify that any 3rd party software (e.g. backup) that you're using supports the new version.
André
In addition to above, refer the below upgrade process for your vSphere environment.
Overview of the vSphere Upgrade Process (vmware.com)