Can anyone provide a brief explanation in layman's terms (as in "management friendly") of just what vSphere is, what can be done with it and why it's better than the alternatives?

Also, examples of possible real-world applications appreciated.

  • Can you name the alternatives that you're faced with?
    – mfinni
    Dec 27, 2010 at 22:12
  • I am afraid not, having a hard time finding those too!
    – JohnIdol
    Dec 27, 2010 at 22:16
  • So, since we're technical, can you explain to us why you want vSphere, and we can help you translate? Are you entirely new to VMware? What are you using it for?
    – mfinni
    Dec 27, 2010 at 22:23
  • What I'm asking is, are your alternatives either ESX without VSphere, or a different platform for virtualization entirely?
    – mfinni
    Dec 27, 2010 at 23:06
  • Sorry, I don't want to sound too negative. If you are asking this question you shouldn't be deploying this by yourself. I would recommend hiring some consultants to help you along with the process.
    – PHLiGHT
    Dec 28, 2010 at 0:29

2 Answers 2


vSphere allows you to run multiple virtual machines on a single piece of hardware. Basically you take a single machine with say 16 CPU cores and 64 Gigs of RAM, and you slice that up into smaller bits so that you can run a bunch of smaller machines on it. Say 10 different virtual machines with 2 CPUs and 4 Gigs of RAM each. Some of these virtual machines can run Windows, some Linux, some Unix, etc all on a single piece of hardware saving you money on hardware, power, cooling, rack space, etc.

The biggest competitor to vSphere is Microsoft's Hyper-V. vSphere is a more mature product which gives it a leg up. The biggest benefit that vSphere has over Hyper-V are:

  • vSphere has a much smaller install footprint that Hyper-V
  • vSphere allows you to vMotion (Live Migrate in Hyper-V language) more machines from one host to another at a time (1 for Hyper-V vs. 4 or 8 on vSphere depending on the network config).
  • vSphere doesn't require physical Windows domain controllers where Hyper-V requires at least one physical domain controller (it is recommended that the vCenter server is run on a physical server however).
  • If you have the vSphere Enterprise Plus edition then you can use the virtual Cisco switch and run a virtual managed switch so that the switch can be managed just like any physical network switch by the networking team.

Now do keep in mind that not every server can be virtualized. Some servers just aren't good candidates for making them a VM, however that said, in most companies there is no reason that most physical servers couldn't be virtualized.

  • 1
    To add to the excellent post above: In management terms, it allows you to minimize investments in hardware by more effectively utilizing fewer purchases. Dec 27, 2010 at 22:37
  • I may have given a presentation or two on virtualization (both on Hyper-V and vSphere). :)
    – mrdenny
    Dec 27, 2010 at 22:39
  • @mrdenny thanks man - this is exactly what I was looking for
    – JohnIdol
    Dec 27, 2010 at 23:16
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    When you build a VMware (or Hyper-V) environment you are building a private cloud for your company. They don't offer a public cloud platform.
    – mrdenny
    Dec 28, 2010 at 9:53
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    No problem, I should have clarified that if you have a Hyper-V cluster you will need a physical domain controller, otherwise you will have a hell of a time getting things up and running after a power failure. Without a physical DC the cluster can't start. If the cluster can't start then the virtual DCs can't be started. So you need a single physical DC to start up so that the cluster can authenticate and start all the VMs.
    – mrdenny
    Dec 28, 2010 at 18:54

MRDenny's answer is extremely misleading as "vSphere allows you to run multiple virtual machines on a single piece of hardware" is a definition for any VM technology (QEMU, KVM, Xen, VirtualBox, VMware player/server/...).

vSphere has a small component that allows running VMs (basically equivalent to QEMU or VMware player), but it is almost entirely a set of tools to configure and manage virtual machines and virtual machine instances. This is done via a set of web GUIs connecting to various service daemons.

Its value is not in the ability to run multiple VMs on a single server (again, any VM technology can do that), but in making the creation and maintenance of those VMs easier.

  • I'm not sure how my answer is misleading. I give a quick overview of what virtualization is as requested (yes I site VMware, but the OP obviously knows there is more than one VM platform out there as he is asking about how VMware is different from competing products), then I go into the differences between the two biggest players without going to in depth so that he's got something to present to management as he requested.
    – mrdenny
    Dec 28, 2010 at 19:01
  • Your answer is misleading because you did not separate the ESX part out. LIke you compare Hyper-V with vSphere, in reality you should compare vSphere with MSVMM from Microsoft, i naddition to the hypervisor.
    – TomTom
    Dec 28, 2010 at 19:03
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    As I see it, mrdenny's answer was on the level the asker needed. A technical answer about hypervisor architecture will not be useful to explain the product to management. Dec 28, 2010 at 19:23
  • my question was about vSphere, not virtualization in general, so I can see @Walex's point, but at the same time @mrdenny gives a definition that goes beyond a simple explanation of what virtualization is, which I already knew, just wanted to know how this is achieved through vSphere. However it would be interesting to see some mention of ESX and how it fits into the bigger vSphere picture in the answer
    – JohnIdol
    Dec 28, 2010 at 23:47

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