1. Download ESXI 6.5 offline bundle from Download VMware vSphere
2. Ensure you have backups of your VMs before upgrading. Shutdown all VMs running on ESXi host.
3. Upload esxi offline zip bundle to datastore on ESXi host.
4. SSH esxi host and execute below command based on the datastore path you have uploaded image to. This is example with datastore name datastore1.
esxcli software vib update -d /vmfs/volumes/datastore1/VMware-ESXi-6.5.0-4564106-depot.zip
5. Upgrade will ask for reboot, after reboot you are done with upgrade to ESXi 6.5
Below are the detail steps if you need reference, even though these are from 5.5 to 6, but are same steps.
You can upgrade your license within MyVMware.
Please consider marking this answer "correct" or "helpful" if you think your query have been answered correctly.
When ever you apply a major update like 4.x -> 5.x -> 6.x the license of the Host will reset to the 60 day Trial which means Enterprise Plus. So after succesfully update a Host you will apply the new LIC later.
Updating a LIC can you do in MyVMware. Within the dropdown in the upper left you have to choose "Upgrade". During this process you have the chance only to update a few LICs instead of all. So you can create 2 CPU LICs for a 6.5 Host and leave 4 on vSphere 5 if needed.
Note: You Essentials Bundle contains
1 Instance vCenter Essentials
6 CPU ESXI Essentials
Here is what I would recommend with regards to your query.
- First check if your hardware is supported for installing vSphere version 6.0 / 6.5.
- Upgrade the firmware on the host with the best suitable and stable releases.
- You can then upgrade the license vSphere 5 Essentials on your My VMware account to vSphere 6 Essentials and then proceed to upgrade your hosts.
About your question, "Can we upgrade the license from VSphere 5 Essential to VSphere 6 Essential in MyVMWare and then apply the new 6 license in the current ESXi 5.1 U1 ?
Is the ESXi U1 accepting a VSphere 6 Essential license?"
You cannot apply a ESXi version 6.x license to a ESXi host running a version 5.x.
In case if you have a problem with upgrade you can reach out to VMware support for help, they can help you with downgrading the license if needed.
Hope this answer's your question.
For the steps, IIRC, upgrading the license doesn't kill your older license (at least not presently). So you'll have overlap time in order to get everything setup/installed. You can also do the new installs/upgrades and have the eval licenses applied for the 30 or 60 days (vCenter and ESXi). The installer is the same for all VMware product families (ESXi is one installer, altered by the license applied, same for vCenter).
For the install process. I would get your vCenter up to 6.5 absolutely first. Then add the second host to it. Migrate VMs that need to stay running to that host, and then upgrade the original host to the new version.
Personally, I've done virtually nothing with the "Essentials" products due to their limitations and being able to get at least Enterprise Plus licenses for products (plus vCenter Standard).