Upgrade (or fresh install) ESX 3.5 to ESX 4.1 Standalone Hosts

[dwinslow]

I have two ESX 3.5 hosts that I would like to get "upgraded" to ESX 4.1.  I know I need to eventually move over to ESXi but I am not ready to do that yet for reasons beyond the scope of this question.

Is there any way to simply do a fresh install of ESX 4.1 while preserving the existing ESX 3.5 datastore?  If not, is this the best path?

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100944...

I am not loving the idea of doing an "experimental" upgrade on production servers.  Thanks in advance for any help you can provide.

[ProPenguin]

Based on your question does this mean you do not have a SAN?  Also could you elaberate on your setup a bit.  I am just trying to think of anything that could help.

[dwinslow]

Correct no SAN - just (2) ESX 3.5 hosts using their own direct attached RAID arrays for storage.

[bulletprooffool]

Personally, I'ddo a fresh installation, using ESXi - ESX will soon longer be available (for updated versions) in the old ESXi format. So if you are going ot be doing a big upgrade, you may as well take the hit and go straight to ESXi.

As an adde dbonus, if you install ESXi on USB / SD, you can remove the current physical disks for the upgrade process and therefore have a proper roll back solution if you need to roll back to 3.5

[ProPenguin]

Hey just an idea.  If the harddrive are not internal drives with the OS on them, you may be able to install the new ESX and reconnect the drives.  That is how it works with the SAN environment.  You will have to reestablish the VMs but all the vmdk's and other files should still be there.  You will want to utilize that support you pay for and confirm this.  I also agree that in your situation ESXi would save you money and probably get you everything you have now, except support but thats your call.  Hope this helps and please confirm it first I dont want you losing any data.