You’re probably familiar with the concept of VM sprawl—the no-longer-hidden cost of virtualization and cloud computing—where the proliferation of system images threatens to wash out the savings promised by these technologies.
As the story goes, virtualization and cloud are an escape value for pent up IT demand, making compute capacity cheap and accessible. As Aristotle taught us, nature abhors a vacuum—when space is made available, it’s quickly filled in.
The result is a sea of system images. Since these images are typically created and modified by hand, image inventories are an unruly and unmanageable mess.
Storage vendors promise to solve the problem through automated de-duplication, which seems to have become the most common answer to the VM sprawl issue. Why? Because large storage vendors have invested heavily in getting us to see it that way. Storage vendors love VM sprawl because it drives storage spending, which is both the truth and perhaps EMC’s investment thesis for VMware.
But treating image sprawl as a storage problem is shortsighted. It addresses the symptom, rather than the underlying cause of the problem itself.
The underlying cause of the problem is the way images are produced in the first place. Today, they’re constructed and tweaked by hand without any mechanism for consistency or control. They’re handcrafted, one-of-a-kind artifacts. Snowflakes.
A better answer is automation—and the total elimination of image inventories!
Consider how automation has completely commoditized books in their physical form. Books were once treasured assets. Not necessarily the content, but the physical book itself. The cost of producing a book made this so. The printing process—even post-Guttenberg and his movable type—was painstaking and laborious.
Fast forward to present day and the book-as-physical-asset is a quaint anachronism. The content may be treasured, but the book itself is a commodity.
Why? Because automation allowed the focus to shift from the book—the thing you can drop on your foot—to the content itself. In this context, the author’s content is the pattern and the book is nothing more than cheap output.
Thanks to automation, this output is generated automatically and in any format. The content is fundamentally reproducible—consistently and automatically.
And that’s exactly what needs to take place in enterprise IT: Images should be generated on demand from patterns—cheaply, consistently and automatically.
Organizations must shift their focus from managing image inventories to managing system blueprints—version controlled patterns that provide detailed instructions for how the image should be constructed.
Need to deploy a system? Generate an image from a blueprint.
Need a slightly different image? Create a new version of the blueprint.
Done with an image? Throw it away! They’re cheap to reproduce.
There’s a strong precedent for this approach in modern manufacturing: Just-in-time production. One of the key tenets of lean manufacturing, just-in-time dramatically reduces inventory holding costs by shifting the focus from managing in-process and on-hand inventories to managing manifests, bills of material, and deeply automating the supply and demand chains.
Manufacturing has taught us that deep description and automation is a better alternative to managing inventories. As scale compounds and budgets contract, today’s IT organizations are wise to rethink VM sprawl—and to recognize that the solution is not in masking the symptom, but in addressing the cause itself.
Breakthrough insight is often about applying an old idea to a new context. For IT, this means looking to principles of manufacturing. In doing so, the idea of managing image inventories becomes nothing short of quaint and anachronistic.
