i don´t think so. I think as Duncan already mentioned in another post this is unfortunately not possible at this time. Check out Re: Virtual SAN Licensing
Yes, upgrading is possible from 5.5 to 5.5U1. But the upgraded 5.5U1 won´t allow VSAN to run as it should.
@Duncan: Correct? Could you jump in and clarify?
I sent a support request, Looking forwards to read the answer
Here is the reply: As discussed, you would need to run vSphere 5.5 Update 1 in order to use Virtual SAN.Virtual SAN does not require a separate download because functionality is included in vSphere 5.5 Update 1. Currently there will be no upgrade/downgrade options for VSAN since this is a new product launch.
Kindly refer to the KB article below for more information :
Requirements and considerations for the deployment of VMware Virtual SAN :
http://www.vmware.com/files/pdf/products/vsan/VMware_Virtual_SAN_Datasheet.pdf (Please refer to Software)
The question still remains unanswered: Is a previously from 5.5 to 5.5U1 UPGRADED vcenter server capable of using VSAN?