Question : VMWare VSphere upgrade

Hello all

I have a question regarding vmware upgrades.  I have 2 VMWare ESX 3.5 servers with a Virtual center server that I am upgrading to VSphere.  However, the virtual center server died in the upgrade, and no longer exists.  So, I have hadware I can use for a new (upgraded) Virtual Center server.  This server also had the licensing server on it.  

There are numerous virtual machines on the vsphere hosts that I need to preserve.  My question is: If I upgrade these esx 3.5 hosts (without the virtual center and licensing server), will my virtual machines be preserved?  And, assuming so, can I just install the vsphere licensing and then be able to power on the virtual machines?

Thanks for your input

Answer : VMWare VSphere upgrade

The most critical aspect of the vCenter Environment is your vCenter Database.

Please update whether you have a good backup of the vCenter DB (SQL or Oracle)

Before the upgrade process, go through the 4 Part Video Series especially uploaded for VMware vSphere 4 Upgrade

http://www.vmware.com/products/vsphere/upgrade-center/resources.html