One aspect of the container ecosystem is the operating system needed to run an application in a containerized environment. These container-specific operating systems allow multiple containers to share the same OS without the need for a hypervisor to oversee each container.
Microsoft’s recent streamlining of its Nano Server and Server Core products highlighted the growing focus on optimizing container platforms.
The move included updates designed to reduce images inside of a container by more than 50 percent. Microsoft also plans to remove the current infrastructure-related functionality from the platform. The service will be available only as a container-based operating system image that must run as a container in a container host.
Many container technology companies have their own lightweight operating systems developed specifically for container deployments. Some examples of these lean operating systems include CoreOS, Ubuntu Core, CentOS, RedHat, Rancher OS, VMWare’s PhotonOS, Microsoft’s Nano Server, Google’s Container-Optimized OS, and Project Atomic.
“Given the scale at which such applications run, it’s important to keep the OS as lean as possible since each unnecessary file will effectively be replicated for each container, which quickly adds up,” Cowen and Company explained in a recent research report. The firm noted this model is also known as “just enough operating system.”
In addition to reducing resource overhead, a well-formed container-specific OS provides organizations with operational security. This is because the OS’s small footprint makes it easier to create save points when updating systems.
“In a production environment that is being continuously updated by developers and software vendors, there is an increased risk that a change will cause an outage, or some other type of undesirable behavior,” Cowen and Company said. “Thus, the ability to roll back recent changes to the last known stable state … is extremely valuable.”
Differentiation From VMs
The container model is different from traditional virtual machines (VMs), which typically call for each VM to have a separate OS and hypervisor. Cowen and Company explained that container technology could be a threat to VMs as it’s a way to virtualize an OS system without adding the additional overhead (and cost) of installing several virtual machines.
“Containers remain a long-term threat to disrupt the server operating system market,” Cowen and Company said in its report.
Virtualization software companies have tried to counter this perception by integrating container technology into their respective platforms. The research firm cited moves by the likes of Microsoft and Red Hat in launching “minimalist” versions of their operating systems to compete with the container-specific Linux OS platforms.
One challenge for the container OS market compared with VMs is the lack of maturity. Many organizations have become comfortable with VMs despite potential limitations. However, the container market remains a new endeavor requiring resource commitment in order to gain experience.
A report from 451 Research did find that organizations are beginning to increase their trust in the container ecosystem. The report, which included a survey of 201 enterprise IT departments, found growing plans over the next two years to run containers either on top of bare metal or in place in VMs.
“We expect this trend to continue as enterprises increasingly move beyond running containers on top of VMs,” the 451 Research report found.