Downgrading ESXi5 to ESXi 4.1

[SKIRK505]

We have been having issues with our new vSphere 5 Environment from inception, and since we have been forced to move into production with it, we are at the point where every recomendation is to downgrade from vSphere 5 to 4.1.

The problem we are seeing with the current environment is detailed here http://communities.vmware.com/message/1853027?tstart=0

We know the Datastores will need to be reformatted (VMFS5 to VMFS3), and Guest Hardware Version will need to be downgraded (Version 8 to Version 7), but we are still unsure of what the best approach is since this is technicaly a production environment.

So I'm looking for any thoughts/documentation on recomended downgrade processes.

[Troy_Clavell]

WOW!  This will not be a fun downgrade.  With that said, I would not except and answer of downgrade to 4.1.  To me, if seems like, if VMware Support is saying to go back to 4.1, it's not a viable answer.  You should also lean on Cisco for help.

If you have no other option then to revert to 4.1,  You will need a 4.1 vCenter instance.  From there, Pull one host out of the cluster, rebuild to 4.1, add the host into the new 4.1 vCenter instance and use VMware Converter to move your guests.  VMware Converter will allow you to downgrade the virtual hardware version to 7.  I wouldn't be too concerned with the VMware tools, but you should uninstall the guest tools and reinstall with the version that matches your 4.1 Hosts. (This work, along with destroying and re-formatting the LUNs will take sometime)

The advise is very high level and a rebuild should be your last resort.  Push Support, both Cisco and VMware to come up with a better answer then downgrading your infrastructure.

[SKIRK505]

I agree, I'm not looking forward to having to downgrade the environment, but Vmware support is stuck on that idea that "It is important to test whether ESX4.1 is ok to charactize the issue".

To me it feels like support wants to validate the build by converting one of the host to 4.1 before going any further. Its just a huge undertaking to for a "test".

We are continueing to do research on our own, trying to hold off on downgrading as long as we can, but right now I can't really get anything else from Vmware support other than, downgrade and see if that resolves it.

[ranjitcool]

Actually it might be easier than you think to downgrade. But it depends on if you have spare hypervisors and spare disk (atleast temporary).

If you have the additional machines, simply load vmware converter on your vms and do a conversion to the esxi4.1 hosts.

It all also depends on if you have windows machines or rhel machines as vmware doesn't support other P2V (v2v technically).

Just use converter and convert them to other hardware. Re build current hard ware and move everything back.

Let me know if that works.

RJ

Please do award points for helpful or correct answers

[AndreTheGiant]

The simple way could be build a new host with new datastore and use Converter to make V2V.

But you will have a downtime during this operation.