Licensing Question...

[pegasus20111014]

We are migrating from vCenter 4.1 to vCenter 5.1.  We are going to stand up a new server for vCenter 5.1 and then migrate the ESXi hosts from vCenter 4.1 to the new vCenter 5.1 server.  We will need to upgrade our vCenter 4 License to vCenter 5, but, it seems we would need to continue to use the vCenter 4 license until after the migration of all the ESXi hosts to vCenter 5.1 is complete.  Is it ok to continue using the vCenter 4 license until the migration is complete,even though we have upgraded the license to vCenter 5 and applied that license to the vCenter 5.1 server?

We have the same question in regards to our ESXi 4 licenses.  Most of our license keys include multiple CPUs (4 or more)  and have serveral ESXi servers using the same license key.  Is it ok to upgrade a license key, that for example was for 6 processors and assigned to three different ESXi servers, to vSphere 5, even though only one of those servers in that group may have been upgraded to ESXi 5.1 and still in the process of needing to upgrade the other two servers?  Or, do we need to go to the My VMware website and separate all of our licenses for each ESXi host?

[SureshKumarMuth]

"but, it seems we would need to continue to use the vCenter 4 license until after the migration of all the ESXi hosts to vCenter 5.1 is complete"

Here you have set up a new server for vcenter 5.1 once you are done with all settings add license to the new vcenter server 5.1. Now you have two vcenter servers (vcenter 4 and vcenter 5.1). Then disconnect the hosts one by one from vcenter 4 and connect them to vcenter 5.1. Since we have two seperate vcenter  servers here so no need to worry about licensing here. Once you complete all migrations, you can decomm the vcenter 4 server.

regarding ESXi licenses:

You can use single license key for multiple ESXi hosts provided only the CPU count matters there, if you have license key for 6 CPUs and you have added only one host using that license, if you have assigned license for 2 CPUs remaining 4 will be unused and you can use that any time, it is not mandatory to add all hosts at same time. There are scenarios where customer purchase licenses for 100 CPUs but not necessary to use all at a time and we can use whenever required.

[swatsson]

Few points here.

1. You can connect 5.x ESXi only to 5.x vCenter, you cannot add them to 4.x vCenter.

2. Whenever you perform upgrade, it is suggested to first upgrade the vCenter and then the ESXi hosts. This is so that after upgrading the vCenter, the 4.x ESX can still be connected to it because vCenter is backward compatible with ESXi hosts.

Now in case if you need to continue using your 4.x vCenter till the migration period is over, cant you put it in evaluation? Even after the evaluation period expires, you can still keep on using it as long as you are not adding any more ESXi hosts to it. Same logic applies to the ESX hosts too. Even if the evaluation period of ESX expires, you can still continue to use them as long as you are not powering on any VMs (existing powered on VMs will still work). Wouldn't that be ok for your migration period?