Was wondering if anyone knew of a cheap XenServer build. Want to build two hypervisors using Citrix XenServer (based on open source Xen project). I was hoping for at least 8gb of ram on each and should have a HVM compatible processor. Let me know if anyone has a good rig. Needs to be cheap cause I am looking to get two to test WLB and HA.
Your build can be as cheap or as expensive as you can afford. A general rule of thumb is don't let your number of VMs (assuming 1 virtual CPU per VM) exceed your number of logical cores.
This leads you to determine how many VMs you plan on having per server. The main resources you are concerned with are vCPU, memory, and disk space:
1.) Memory: 1GB or less is generally acceptable for a test VM. Obviously, 2GB or more if you are going to use a heavy production VM. 8GB would be enough for a few production VMs or several test servers. You could use more if you plan for growth.
2.) CPU: I cannot stress this enough: Make sure your CPU supports "virtualization technology" or some equivalent terminology. Also, make sure it is enabled in the BIOS. XenServer will work with almost all CPUs, but will not receive the performance benefits of VT unless the CPUs are capable and enabled.
3.) Storage: Local storage is easy and you should look into an inexpensive RAID controller should you go this route. The other option, depending on if this system will be in heavy and/or long-term production, is to use a NAS or SAN (these are not cheap options, but are reliable and good for High-Availablity usage.
Look on CPU Benchmarks for CPU cost/performance estimates. You could build cheap, effective towers to run your VMs for less than $1000 each. Server chassis/hardware will add a great deal to your costs, but it is generally more reliable in an enterprise environment. As always, cost/benefit is key here: Reliability vs. expenses, Wants vs. needs, future developments vs. current requirements, etc.