Can we install a new vCenter and add existing ESXi hosts to it ?

[SahanVMTN]

Hi all,

Recently we upgraded our 5.5 vCenter to 6.5 vCenter and the installation got failed. The appliance was deployed successfully. vCenter server appliance looks healthy and all its content seems fine. But, we are unable to login to the vCenter from any browser. We have tried rebooting the VCSA and restart its core services by SSH. But the issue persists.

We had a three ESXi hosts cluster with a SAN attached to it. We powered off the vCenter 5.5 server VM and took a snapshot backup of it prior to the 6.5 upgrade.

Now, we only have three ESXi hosts and VMs running on them without a vCenter management.

Below are the doubts we have:

Can we power on the 5.5 vCenter server appliance and revert it back to the snapshot which we took prior to the 6.5 upgrade? if so, would it take the IP address back, which was exported to the new 6.5 appliance during the migration process?  

If not, can we do a fresh installation of 6.5 vCenter server appliance and attach the ESXI hosts to it ? If so, are there any dependencies (vCenter settings, Network settings, ESXi hosts Licensing, vCenter Licensing) we need to be aware of ?

[dbalcaraz · Accepted solution]

Hi,

Well you could use your VCSA and so on but, some inconsistencies may you found.

I would suggest you to re-build the VCSA but if you don't have any backup of the vCenter settings, you must redo all the network, storage, vCenter/License settings again.

If this is only a cluster with three hosts, it shouldn't take you too much to re-build the entire cluster and redo all settings.

Another thing you can do to speed up the process is, restore the old VCSA in a isolate network, backup settings as vDS for example.

[SahanVMTN]

Hi dbalcaraz,

Thanks a lot for the information. I will give a try and see how it goes.

Regards,

Sahan

[roland_geiser]

Hi

Can we power on the 5.5 vCenter server appliance and revert it back to the snapshot which we took prior to the 6.5 upgrade? if so, would it take the IP address back, which was exported to the new 6.5 appliance during the migration process? 

I think yes. Especially when you did not yet upgrade your ESXi Hosts, this should work.

If not, can we do a fresh installation of 6.5 vCenter server appliance and attach the ESXI hosts to it ? If so, are there any dependencies (vCenter settings, Network settings, ESXi hosts Licensing, vCenter Licensing) we need to be aware of ?

I would also recommend to re-install or do a new-install of the VCSA. Your environment with only three hosts seems not to be very complex. And if you use standard switches, their configuration is already ok and you will see the portgroups all on the new VCSA.

If your old vCenter is running it is also possible to setup a new VCSA in parallel (new IP and hostname)  and then just detach a host (with all the vms) from the old vCenter and attach it on the new VCSA. All VMs should be visible in the new VCSA now. This as a proposal if you cannot get the upgrade to work.

best regards

[SahanVMTN]

Hi Roland,

Thank you very much for your comments!

The upgrade was successful ! Below is the DNS issue which we came across during the upgrade validation process. We had to make sure the DNS records have configured correctly. Although, VMware would let you proceed with skipping this warning. But, you will face troubles when accessing the vSphere web client landing page.