Can vSphere Update Manager Downgrade ESXi 5 to 4?

[Cannoli]

Just curious if it's possible.  I would move the VM's off of the host first as the drive formats aren't compatible. I'm curious as to the process itself.

[Cannoli]

Looks the answer is no, the ESXi 4 image won't import...

[a_p_]

I'm not aware of any possibility to downgrade a host, neither through Update Manager nor manually. If you need to "downgrade" this would have to be a clean installation.

André

[RanjnaAggarwal]

No it cannot downgrade it to esxi4.

Hope you get the answer of your query

[BaSergey]

Some time ago i made this, just for training, not for production.

I've made clear ESXi 5 installation and created a guest.

After that I booted host from ESXi 4 CD and made a "Repair" installation.

Datastore remains healthy.

You cat try it youself in VMWare Player if you doubt.

[admin]

Hi Cannoli

I dont think there is any option call downgrade ,if so then only one optio that is clean installation.

"Life is never easy for those who dream"

[BaSergey]

It IS possible, with some hands and brain.

First, backup everything, sure you know that.

Boot host from ESXi 4 CD and choose "Repair". You'll got clear ESXi 4 installation but data on datastore still untouched.

Now enable Tech Support Mode, open shell with Ctrl+F1, log in under root account.

cd /vmfs/volumes/datastore1 - here your VMs is.

Use vi to edit *.VMX files and change config.version and virtualHW.version to "7".

Now browse datastore and manually add your VMs to inventory. Try to boot guest.

In most pessimistic scenario you can create new VM and add old .vmdk to it. Than boot from any recovery CD and copy data.

I must add that it is NOT ready-for-use guide, but hope it helps.