I want to deploy 10-15 VMWare hosts to cloudstack. This is my first time working with any type of cloud. I was doing research on installation and architecture, I was stuck on a point that for using VMWare hosts i have to install VCenter server, but i can't do that as it's paid. So, please guide me that is there a way of deploying these VMWare hosts on cloudstack without buying any licensed software.
Unfortunately, CloudStack does not support vSphere/ESXi without vCenter. There were several requests to support vSphere/ESXi without vCenter - however, keep in mind that many features vCenter provides must be implemented in CloudStack and it not an easy task.
If you want to remain open source and or/free, consider using Xen with XenCenter or just go pure KVM. I use to use VMware for most of my career and recently transitions to KVM - it was an easy switch and with no regrets.
CloudStack mailing lists are best to answering any setup questions you might have.
All best -ilya