Will Containers replace VMs…?

In 2007 I embarked on a whistle-stop trip to meet with Xen Source in California to sell their hypervisor in the UK, shortly after this they were acquired by Citrix. This was the time when server virtualisation was becoming mainstream with CTOs accepting that it was time to use VMs in production rather than just for ‘test and dev’. The move to VMs was not instant, but there was significant momentum in this direction and building your preferred hypervisor (at that time almost exclusively VMware) into the infrastructure became the norm.

Right now, it feels like we are approaching a similar point to the one we were at eleven or twelve years ago, the point where containers are going to disrupt VMs in the same way VMs disrupted dedicated hardware.

So, if containers the new kids on the block, what does this mean for the VM?

Firstly, I guess we need to understand what containers are and why we need them. I’ll answer the second half of this question first; as organisations look to get the best from their hybrid cloud solution and utilise the power and agility given by their own Hyperconverged infrastructure or public cloud providers like Amazon and Microsoft the need for a smooth transition of services between different infrastructure becomes imperative. By design containers are extremely “light” and are only megabytes in size so therefore will take a few seconds to start rather than VMs which take minutes to run and are significantly larger than a corresponding container.

Containers are different to VMs because rather than virtualizing the underlying computer like a VM, only the OS is virtualized in a container. So, the container sits on top of a physical server and the host OS, either Linux or Windows. And because a container shares the host OS kernel and shared components are read-only this significantly reduces the need to reproduce the operating system code, meaning a server can run multiple workloads within a single OS. The result is that all the container requires to run is enough of the OS, supporting programs and libraries, and system resources for that specific program. In practice this means you can put two or three times as many as applications on a single server than you could with a VM. This creates an environment which is a portable, and consistent operating environment for development, testing, and deployment.

Some of the benefits of containers include;

• IT management resources are reduced
• The size of snapshots is reduced
• It is much faster to spin up apps
• Security updates are reduced & simplified
• There is less code to transfer, migrate, upload when moving workloads

Today nobody will deny that VMs have been, and will continue to be, extremely valuable for consumers of all sizes. So, in the short term most organisations are likely to include both containers and VMs. The common view is that today the flexibility of VMs and the minimal resource requirements of containers will be able to work together to deliver environments with maximum functionality.

If your organization is running many instances of the same OS, then it is time to investigate if containers are a good fit. You might just find containers can save you significant time and money over VMs. If you are interested to learn how illapa can help you manage your hybrid cloud solution then please drop me a line to will@spectrami.com