From Cumulus blog:
The modern data center is a collection of compute elements connected via a network. What used to be a thread is now a process running inside a virtual machine or a physical machine, and storage lives locally in a server or on a SAN. So what is needed is simply an ability to consistently and coherently connect the compute elements to each other and to storage irrespective of where they live and how they are physically connected. And voila, you get fast application delivery!
To achieve this goal, you just need two layers:
A physical connectivity layer that uses standard mechanisms (let’s say IP/ethernet) and allows all end ports to connect to each other with massive bandwidth, multiple paths and QoS.
A controller that connects subset of ports to each other exclusively and securely using logical ports layered on top of the physical connectivity layer.
Cumulus Linux is the first Linux Distribution for networking gear and it’s finally bringing the economics of Linux to networking. It takes an industry standard networking box and makes it look like a server with a large number of 1G, 10G, or 40G NICs connected at wire-rate. The operating system accelerates the datapath in networking hardware using the existing Linux kernel constructs. So, Cumulus Linux IS Linux and customers can use the best automation, monitoring and orchestration tools onto their networking gear.