Downgrade of Exsi 5.0 to Exsi 4.1

[Legion2]

Hi,

   We made a mistake on upgrading the 4.1 to 5.0, now we need to downgrade it back to 4.1.  My question is, will the created VM machines be affected? I've already created Domain Controllers and Fileservers inside the Virtual Host.

thanks,

[weinstein5 · Accepted solution]

Welcome to the Community - It will require a reinstall of ESXi - the VMs should be ok as long as you did not create your virtual machines with Hardware Version 8 - if you did it is not compatible with ESXi 4.x and if you are using VMFS 5 that too is not compatible -

[Legion2]

Hi, I will again install the Exsi via CD to the SD card in the server.

How can I check the hardware version?

I am using Vsphere 4.1

[jrmunday]

Look at the summary tab of the guest VM, it will show you the hardware version.

[Legion2]

Saw the VM Version = 7

I guess it can be successfully downgraded...

[jrmunday]

No, it means that the VM is compatible with your 4.1 host and can be migrated there.

[Legion2]

Ok, my understanding is that with Hardware Version 7, you can still downgrade your Exsi 5.0 to 4.1 w/o corrupting the created VM's, is this correct?

[jrmunday]

Yes, although the term "downgrade" is not actually valid ... you will need to re-install the host.

[continuum]

downgrading the virtual hardware of the VMs is the easy part - if you have a VMFS 5  datastore that is the bigger problem

[Legion2]

Ok, where can I find the VMFS version of my data store? Also, what version do I need for a good downgrade?

[continuum]

ViClient - select host > configuration > storage > find the datastore - one of the tabs there displays the VMFS version
with VMFS 3 everything is fine - with VMFS 5 you need to reformat the volume - which means that you have to move your VMs to a temporary path ...

[Legion2]

Hi, as per checking... all my datastores are VMFS3... so this will definitely be a smooth re-installation...

[PRAVIN1CA]

As long as following criteria meets!!!

VM Hardware Version = 7

VMFS = 3

Install ESXi-4.1 on temp location ( USB Key ) ... Make Data Store Device visible to hosts!!!

Scan for datastore 🙂  & You are there....

[Legion2]

HI,

   The Exsi 4.1 will be installed in the SD Card of the Server. How will I make the data store device visible to host and also scan?

[PRAVIN1CA]

I am not sure about your hardware details...

SAN Storage, Disable SAN Switch Ports & install 4.1 then enable SAN Switch Ports & scan for datastore & host will recongnize them if they are still VMFS3

Depend upon storage type different methods can be used.

Thanks