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I want to configure a system for cross-browser testing of rich internet applications in browsers. My requirement is to have one system with 20-30 virtual machines (eg, with VirtualBox). There will be a need for up to four concurrent virtual machines each running tasks like: automated scripts that drive browsers, humans driving browsers, image processing, a JVM, etc.

So to summarise that's 20-30 VMs with up to four concurrent VM sessions. What kind of specification machine would suffice?

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Is this all going to run on your desktop to be used by you alone, or running on a virtualization host server to be used by others as well? – Bret Fisher Mar 16 '11 at 19:46
Oh and are you expecting a specific host OS, that is are you more Windows oriented or Linux, etc. Lots of ways to skin this cat. I prefer Windows but many here will help with Linux host solutions. – Bret Fisher Mar 16 '11 at 19:49
1. Running a virtualization host server with up to four concurrent users 2. host OS doesn't really matter. – st9 Mar 17 '11 at 16:33
up vote 0 down vote accepted

I would setup a Windows Server 2008 R2 host with the Hyper-V role installed. Installing the new SP1 will give me Dynamic Memory to allow running more machines at once by optimizing RAM in each VM (Vista or Win 7 clients only).

CPU: A quad core single CPU modern server should work fine but opting for 2 CPU's would allow more CPU headroom if you're doing CPU intensive JVM stuff, etc.

RAM: With only 4 VM's running concurrently you could try to get away with 4GB of RAM total but I would go for 6-8 since it's so cheap with 512MB for host OS and ~1GB for each client VM based on your needs.

Disks: Disks are nothing special in your config if only 4 users at a time. I would opt for 4 7200 or 10k RPM drives in a RAID 1+0 config for redundancy + performance. If you don't care about hardware failure, go RAID 0. You'l need lots of space if you have 30 virtual hard drive files on that box.

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Are non-Windows OS supported under Hyper-V? For example Mac OS X and Unix – st9 Mar 18 '11 at 16:45
I don't know any product that officially supports Mac OS X. Linux flavors are supported by the Linux Integration Services.… Red Hat and SUSE are officially on the list… but I've read you can get it working on others. ServerFault has lots on the topic: – Bret Fisher Mar 18 '11 at 18:34
Also, a Microsoft technical video on using Linux and UNIX in Hyper-V – Bret Fisher Mar 18 '11 at 18:36

You can use XEN on debian and run vservers. With paravirtualisation you can run Windows or other operating systems on the system. 20 - 30 mashines are not the problem but then you need a lot of ram for it.

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There are a lot of variables to determine your base spec. What OSes are going on the VMs? Are you doing any load testing, or is it just single sessions for QA purposes? If you want to do load testing, how many concurrent sessions are you going to script up to?

I'd assume you are rolling out a 64-bit linux distro to minimize the host footprint. You'll obviously need more resources if it's a Windows box.

I'd say at the very least you'd need 8GB of RAM and two dual-core CPUs. For as many total VMs as you are looking for you need a lot of storage.

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  • The total number virtuals determines the disk needed.
  • The total number of running virtuals determines the memory.
  • You need a 64bit processor with VT/SVM support to run 64bit clients
  • A decent video card will ensure no CPU load from video and easy multi-monitor setups.
  • motherboard with gigabit lan and sata support

Example prices:

  • 4gig ram = $35
  • 1tb 7200rpm disk = $60
  • gt430 video = $50
  • motherboard = $50
  • quad processor = $100

More than sufficient. Entire system could easily be built for under $400. As a comparison we have a five year old server running a single core 64bit amd with 4gb ram running 4 or more - 32bit VM's simultaneously with no problems.

  • Don't overspend. Hardware gets cheaper and faster each year.
  • Don't underspend. Sometimes initial costs are justified by reduced maintenance.
  • Don't buy cutting edge hardware unless you really need it.
  • Same cost - Four cheap systems can outperform a single high-end system for many tasks.
  • Special needs - dbserver - a single high-end system can outperform a cluster of four cheap systems.
  • Linux as the host will give you the most performance per dollar.
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