When going from ESXi 4.1 to 5.1 there is a few things to remember. I am not sure what version of the hit kit you are running, but it is recommended to delete  the HIT Kit VM then you will need to upgrade the MEM Kit to 1.1.1. Once that is done you can do the upgrade to ESX to 5.1. Then install the new HIT Kit 3.5 VM and configure it. If you have any questions or concerns please let me know as I would be happy to assist you.

Ok Thank you.

I was under the impression that the drivers(MEM) for 4.1 and 5.1 were not compatible, and therefor i had to do a full reinstallation and reconfiguration of my vmkernel ports, but i am glad to hear that is not the case.

Phew that is a relief atleast. i did not save my configurations, and i do not find restoring configurations that funny.

Do you guys recommend using the Dell bits DVD (en.community.dell.com/.../dell-customized-bits-for-vmware-vsphere-5-1.aspx)? i have a bunch of older M805 blades and some r715 i need upgraded.

If you are doing an upgrade i would go the recommended path thru first doing the vcenter stuff.

Then upgrade update manager.

After that create a iso baseline with the iso you mention in your post then upgrade your hosts with that .

If you want to do this non disruptive that of course requires that you have the licensing of vmotion and so on setup and of course an interface configured with vmotion.

So put one host in maintenance mode and start the upgrade process.

You can also use the offline bundle vib for creating an extension baseline in update manager for adding the MEM plugin and add that to the host when the host has been upgraded to 5.1.

The alternate path is reinstalling the hosts but that would mean that you have to recreate your iscsi settings of course and everything else as well :).

Hopes this helps you out a bit.

Regards Boris