Welcome to the Community - I would look at VMware Player - it is VMware's free hypervisor - if you want to purchase a product and get the related support I would look at VMware Wokstation -
Thank's for your reply.
AFAIK Player is not free for use in a commercial environment (I first thought, that was starting at version 5, but I think this also was the case already for previous versions).
But that's not the problem! Player is not designed to be used on console-only servers. I usually don't boot to a GUI on these CentOS hosts.
I tried player already and got it to work in such an environment, without GUI, just from the shell - but that's not the way it's supposed to be used and administration is somewhat tricky.
I haven't used Workstation for a while, but I don't think it's working well in such an environment either.
Then you should take another look at workstation - it now has the abilitry to function as server hosting VMs - or you can move to the bare metal hypervisor and run ESXi which will install directy onto the hardware eliminating the need for CentOS - there is a free version available of this as well -
I tried ESXi already, but it's big advantage of being a bare metal hypervisor is at the same time it's biggest disadvantage as it doesn't offer a free choice of file systems or things like DRBD, iSCSI volumes on the host and some other stuff.
But thank's for the hint to Workstation. I have had a closer look at the product description and it pretty much seems to be well suitable for my needs while the price is moderate. I will definitely give it a try!