is this possible? I looked at the compatibility matrix and saw that it can be possible (I might have misread it). I get an error when add hosting in my vCenter
Soory, that won't work. You need vCenter 4.1 to be able to add and manage 4.1 hosts.
In table 2 of the compatibility matrix there's only one "Yes" in the "ESX 4.1" line. That's in the vCenter Server 4.1 column.
As a.p. already posted, you cannot manage ESX/ESXi 4.1 hosts with vCenter 4.0 (or previous) vCenters... The vCenter Server needs to be at least at the same level as the newest ESX/ESXi host revision in order to manage the newer host versions...
So, with vCenter 4.1, you can connect up ESX/ESXi 4.1 hosts, as well as 4.0 (all update levels) hosts... If you have it properly configured, you should also be able to connect 3.5 hosts to the vCenter 4.1 server...
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