Virtual Machine Addiction: We've gone too far.

Virtual Machine Addiction: We've gone too far.

Summary: You're addicted to virtual machines. You spin up a new one for every little niche workload. It's like any other addiction, it's costing you and the price is too high to pay.

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If you've read this column with any regularity, you know that I'm a proponent of virtualization. I'm a proponent of the Cloud. I'm a proponent of virtualizing every workload that can possibly be virtualized. I'm also a big proponent of being smart about computing. You can take virtualization too far. You can virtualize workloads that don't need virtualization. We're addicted to virtualization. It's just too easy to perform a physical to virtual (P2V) conversion, to create a new VM from a template or to spin up a new VM from a standard request. It's just too easy, and now, we're addicted and it's hurting our business.

Does it sound like I'm backing away from an earlier post stating that you should virtualize any and all workloads? Or does it sound like I've allowed myself to be influenced by a small faction of Ken Hess "haters" who'd rather argue than listen?

It could be that I've caved in and relented. It could be that I've simply revised history.

Or, it could be that I have something else in mind?

What I have in mind isn't leaving those workloads on physical systems. No, we've past that milestone long ago. My remedy for VM addiction is simple: Consolidate low overhead services onto single VMs.

There, I said it. Create a few high-end Utility VMs on which to host some of your services.

There's no need to create a separate VM for each and every service that you run. Doing so causes what's known as server sprawl and that's not a good thing. You don't need an individual VM to run DNS services. That's a waste of resources. And, if you're using a Windows-based VM, it's a shameful waste of a license too.

Learn to couple your services. After all, server consolidation and more efficient system use are two of the big reasons why you chose virtualization in the first place. Isn't it? Sure, it is. So, why go into virtualization with your stern consolidation, efficient computing and money-saving collar on, when you're really just going back to business as usual? And, "business as usual" is a term which here means, wasteful.

Think about what you're doing with a new VM before you create it. In addition to DNS services, what else can you run on that system? Active Directory? MySQL? A CMS? SharePoint? It isn't a big stretch of the imagination to believe that you can run multiple services on a single VM. You can and should.

Here are ways that you can test multiple workload compatibility on a single VM:

  • What kind of load do the services place on a system (CPU, Memory, Disk, Network)?
  • Do the services share any TCP ports?
  • Do the workloads require multiple CPUs?
  • Should the workloads have their network traffic separated by VLAN?
  • Do the services require user interaction through local accounts?

Answering these questions will start you on the right track toward placing multiple services on a single VM.

Don't be afraid to mix and match those workloads. You can place a CPU-intensive service on the same system with one that uses a large memory share. You can also place a service on the VM that requires a decent amount of disk I/O. Now, you wouldn't want two services that are CPU hungry or memory hogs on the same VM. They would contend for resources and you don't need that headache.

So, the key takeaway here is to consolidate dissimilar services onto utility VMs. Separate similar services onto different ones.

Addiction is hard to shake for everyone and virtual environments are not immune to its negative effects. It's just too easy to allow the creation of another VM rather than to execute restraint. Save yourself from VM sprawl, save license fees and save money by saying "No" to VM addiction.

See Also:

Topics: Hardware, CXO, Cloud, Emerging Tech, Storage, Virtualization

About

Kenneth 'Ken' Hess is a full-time Windows and Linux system administrator with 20 years of experience with Mac, Linux, UNIX, and Windows systems in large multi-data center environments.

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11 comments
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  • Security implications

    We used to do this on un-virtualised servers. Unfortunately, the more services on the server, the more likely it is that multiple exploits can be combined to break it wide open.
    willavery
    • group according to security, as well...

      @willavery

      group your data and software in accordance to their access rights, as well. If you have a single program/process which requires higher-than-normal security, don't put any low security services on that VM, or better yet, have the high security stuff on physical machines, further isolating it.

      The blog post never said to ignore security requirements, and security requirements should trump the desire for simplicity/convenience...
      shryko
      • RE: Virtual Machine Addiction: We've gone too far.

        @shryko

        Security is of utmost importance, of course. But, physical systems are no more secure than virtual ones. The only way to truly secure a system is to unplug it from the network and lock it in a closet. Secure, but also useless.
        khess
    • RE: Virtual Machine Addiction: We've gone too far.

      @willavery True that. Although sometimes it makes sense for a portal webserver to have MySQL on it if it's not storing anything sensitive (and you don't need multiple DB servers).
      snoop0x7b
    • RE: Virtual Machine Addiction: We've gone too far.

      @willavery

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      filhomarques
  • (Taps Mic....) Hi, my name is Dietrich and I am a VM Junky

    (The crowd roars, ....HI Dietrich.....)
    Dietrich T. Schmitz, *~* Your Linux Advocate
  • (Taps Mic....) Hi, my name is Dietrich and I am a VM Junky

    (The crowd roars, ....Hi Dietrich.....)
    Dietrich T. Schmitz, *~* Your Linux Advocate
  • group the workloads & put them in the right place

    For server-hosted applications, it definitely makes sense to group the workloads based on their security levels to conserve overhead, but for desktop virtualization workloads, a better way to conserve resources is to use the compute power on client machines.

    With VDI implementations, companies are often hosting desktop workloads on servers, but Intel's been advocating intelligent desktop virtualization, which moves the execution of the virtualized desktops back to the client. Virtual Computer is doing this with NxTop, which combines client-hosted VDI and centralized management. Security is protected with a type-1 client hypervisor that has government grade security features like built in AES-256 full disk encryption, USB filtering, time-based lockout, and remote wipe. Moving this desktop workload out of the data center results in over 90% savings in server, storage, power, and cooling costs.
    SRSao
  • I keep asking no one answers, WHY DO WE NEED VIRTUALIZATION

    "If you?ve read this column with any regularity, you know that I?m a proponent of virtualization. I?m a proponent of the Cloud. I?m a proponent of virtualizing every workload that can possibly be virtualized."

    Well you can't see the forest for the trees.

    FIX THE OS (Windows/Linux/whatever), TEACH DEVELOPERS HOW TO WRITE APPLICATIONS.

    Why do you need a seperate OS for every application (an exageration, but), why do you need multiple OS's on a box.

    z/OS has for decades run hundreds, thousands of applications side by side, concurrently with out issue's.

    WHY CAN'T WINDOWS OR LINUX DO THAT ??

    I am not saying to go back to mainframes, although the cloud is nothing more than a mainframe (if it walks like a Duck !).

    Virtualization is fixing a SYMPTON it is not fixing the PROBLEM.
    knudson
    • RE: Virtual Machine Addiction: We've gone too far.

      @knudson

      Good question. And, I'll answer it in the next exciting episode of, "Virtually Speaking."
      khess
    • RE: Virtual Machine Addiction: We've gone too far.

      @knudson
      Other people can post without having spelling errors.
      Other people can post without unnecessary apostrophes.
      Why can't YOU do that?

      Great post. A pity you ruined it by making it almost unreadable.
      rahbm