Hi,
The best Virtual solution nowadays is:
Hardware needs:
MB + CPU both support Intel-VT or AMD-V technology
Example:
MOTHERBOARD : SUPERMICRO X7DBE-X ~700$ per unit
CPU: 2x INTEL XEON X5355 BX80563X5355A ~1000$ per unit
RAM: 4x KVR667D2D8F5K2/2G ~200$ per unit
total 3500$
Software needs:
OS: Gentoo minimal CD 2006.1
Virtualization software: Xen
Knowledge needs:
Hardware: average (needed to assemble the parts of the system)
OS: good (requires quite a good level to correctly optimise the Gentoo Linux)
Virtualization software: good (you have to know how a hypervisor works, and what you need to do to be able to create virtual machines)
Time required to successfuly achieve the project?:
Hardware: depends on how much quality you require from your systems; a fully loaded system with SAS JBODS and other fine hardware inside in a 19" chassis will take 2 DAYS to be built better than any IBM or something will do.
OS: that's the very long part of the project time; to fully optimize the OS for your hardware, you will need to recompile the full base system and compile every single software for your hardware. To have a fully prepared with X and all the nice admin tools you will need: 5 DAYS.
Virtualization software: If like me, you're just trying to find an exit from the VMWare products, you will find Xen very difficult to set up, and quite confusing too. Those with ESX experience will, nevertheless, find that the Xen setup is not that harsh, because, more or less, the ESX setup steps will have to be done for XEN as well. With XEN, things go just a bit deeper. If you never tried something like this before you'll need about 7 DAYS to work before you see your first virtual machine. If you already have some knowledge, you'll need 1-3 DAYS.
BENEFITS ???:
What? about 2 weeks of work for a rookie with computers? Yes, and even more if you never touched a linux in your life. But, Xen running on an optimized Gentoo Linux is something you won't regret to have. The performance gains are not somthing like 30% faster than VMWare on a Red Hat or Windows Server or ESX. The performance gain is 10x faster (depends greatly on your hardware configuration) than ESX. ESX runs fine with 4 heavily loaded Windows Server guests, which is not such a bad ratio: 1 real computer with 4 virtual computers on it, and twice the amount with Linux guests. But with ESX you will need to take care to use the top storage solution on the market to hide the huge lack of performance from the vmfs file system. You will feel frustrated that your 16 SAS hdds in RAID 5 perform so baddly, and then you will go XEN. Alognside the awful I/O performance of the ESX vmfs file system, you have the awful recovery performance of the ESX vmfs file system; if something at the ESX vmfs file system occurs... and the vmsfchk and other useless vmfs commands don't work... the VMWare support will tell you this: reinstall the ESX (for you it will be understood like a: you're ****, your data is lost, have a good day). This is said from sad, sad personal experience.
With Xen, there's no file system problem or some prorietary secret crapy piece of software that will sabotage the performance of your hardware. Xen will work as works your Linux, because it is basically a linux, using the same good file systems you know, the commands and software you know. So, Xen is not such as new world as that, when you need to operate the system part (drivers and configuration files), it is the linux you compiled your Xen kernel on. Yes, Xen is just a kernel that your prepare like any other linux kernel, and that you boot like any other kernel.
Here are the quick steps to install Xen:
1. Build the hardware, check the hardware matches the needs above.
2. Decide how and where you will store your virtual machines and data
3. Install and compile your Linux (Gentoo recommended for best performance over any other Linux distro at a huge compilation time cost)
4. Prepare your RAID devices with mdadm if needed
5. Prepare a portion of your storage with LVM2 (this will be used to install virtual machines on virtual partitions rather than inside files like does WMWare, LVM2 may reduce the performance of your storage (some say up to 50% slower), but will help you create, manipulate, duplicate, delete, virtual machines much faster. Otherwise you can use the normal file method.
6. When you're sure, you have installed all the needed packages (don't forget X server if you intend to use Windows virtual machines) inside your Gentoo, that they have all been optimized for your hardware, you can install the XEN sources and begin the installation of XEN.
7. You should have a working (it boots!!!) XEN kernel now. Know that some hardware support inside the Xen kernel may not be present while you had it working inside your Gentoo kernel. This will require a little search among the forums (don't abandon yourself to frustration, go on). Remember, XEN will virtualize some devices like hard drive, network interface, storage controllers, etc, this means, the hardware you have, may not work inside Xen, so make sure you have the latest sources of XEN, look for patches and don't use the kind of hardware that has been produced at 10 pieces in the world or that is selling only for the last 24 hours (one year old technology should be safe to use).
8. Now to manage our virtual machines like VMWare does, you will need to install XenMan (requires X, and some package manipulation in Gentoo, should work out of the box for Red Hat). Know that XenMan is still limited; the settings you'll be able to alter and actions you'll be able to do on virtual machines are quite limited (lvm partition creation must be done from the outside of XenMan).
If any one is looking for some Xen virtual machine configuration files for Linux or Windows, just post a reply here.