I seem to run into this over and over again. Clients that are confused about whether to put VirtualCenter (now called vCenter) on a physical server or a virtual machine. It has always been my practice to create vCenter as a Virtual Machine within the VI environment. I have always felt that one of the goals of virtualization is server consolidation and management and to allocate a physical machine to manage it all seems almost hypercritical.
When speaking with customers I often site the advantages of virtual machines over their clunky metal counterparts with the following :
- High Availability – Most clients do not realize that HA will function after initial setup without VirtualCenter and as a result will protect VirtualCenter from hardware failure. If the Host that is servicing the Virtual VirtualCenter crashes and burns, HA (running on all ESX hosts in the cluster) will direct one of it’s members to power the VirtualCenter VM back up. Crisis averted.
- Portability – Once a VM, VirtualCenter can be replicated and become part of your backup and DR strategy. With Storage vMotion and “vanilla” vMotion, you can now even use VirtualCenter to move itself from LUN to LUN or Host to Host without having the universe implode on itself.
- Manageability – upgrading vCenter, no problem, just take a quick snapshot and go. Need more memory or CPU cycles, just move the sliders up! Hard drive filled – Glad it’s not a physical box. :)
- Policy – VirtualCenter is an IT server and if it manages to go down, the rest of the environment continues to function. Administrators can always revert back to attaching to individual hosts to perform basic management tasks on the environment until someone powers the vCenter back up.
- Support – VMware fully support either configuration in any environment.
- The VMware roadmap is to release a Linux based VirtualCenter Appliance. Might as well stay ahead of the curve! :)
In LARGE environments with dozens of hosts and 1000s of virtual machines, physical VirtualCenter servers might have their place but for the majority of my clients, a vCenter VM makes a lot of sense.