Cloud computing moves systems to a new architecture -- but in many cases their technologies aren't designed to work in the new cloud environment. Virtual machines such as the Java Virtual Machine and the Linux and Windows operating systems can be made to work there. But what if someone designed an operating system specifically for the new elements of the cloud environment?
Cloudius Systems is attempting to do just that with its OSv ("operating system virtualized"). OSv is being developed by the folks who figured out how to embed KVM hypervisor in the Linux kernel: Avi Kivity and others at Israeli startup Qumranet (which was acquired by Red Hat for $107 million). Qumranet was founded by Moshe Bar, a guru of the open source Xen hypervisor, and Rami Tamir, a former director of engineering at Cisco. After two years at Red Hat, several Qumranet team members, including Kivity, Dor Laor, and Benny Schnaider, moved on and founded Cloudius Systems, in December 2012. Laor serves as CEO, Kivity is CTO and Tamir is an investor in the startup.
The central idea behind Cloudius is based on the premise that the operating system embedded in the virtual machine was not designed for that task. Likewise, the hypervisor and runtime environment, which is frequently the Java Virtual Machine, were not designed for an elastic, virtualized cloud setting. As a result, the operating system, Java Virtual Machine and the hypervisor perform many of the same tasks, duplicating work and generating operational overhead.
[ Want to learn more about how Red Hat acquired hypervisor expertise? See Red Hat Acquires Virtualization Pioneer For $107 million. ]
Qumranet found a way to improve the efficiency of hypervisor operations by embedding the KVM hypervisor in the Linux kernel, enabling it to use the scheduler and memory management of the kernel rather than duplicating those functions. Cloudius wants to do something similar to the cloud computing software stack. As the company put it in a presentation: "Too many layers, too little value."
One of the main culprits is that operating systems are designed to manage multiple applications at the same time -- but that's not how they're used in virtual machines. "There's only one application being run typically in a virtual machine," Laor noted, "with most implementers putting multiple VMs on a host." The isolation and application protection features of the operating system are then duplicated in both the JVM and hypervisor. It takes a lot of CPU cycles to hand off responsibilities for application functions from one layer to the next.
Most operating systems have a scheduler that watches multiple applications for purposes of scheduling their threads in a manner that keeps them separate. But what if the operating system recognized what the hypervisor was doing and restricted its own activity accordingly? "You do pay for all the operating systems' mechanisms even though you don't need them," Laor observed.
OSv is not a stripped-down version of Linux, nor is it a knockoff of some other operating system. Rather, Laor explained, it is a new operating system kernel geared to the needs of the virtualized cloud workload. It has taken the widely accepted TCP stack from Free BSD, along with its open source ZFS file system, which originated at Sun Microsystems but is in most respects a new kernel.
OSv recognizes when a Java Virtual Machine is present and hands off management of page table blocks to the JVM. Laor explained that as they're currently engineered, both Linux and Windows block the JVM's access to page tables and continue to administer that function, even though the JVM can do it more efficiently for one application.
OSv, which will be open source code, is coming out of stealth mode on Tuesday. It will have limited general availability – i.e., general availability to some customers cooperating with the company -- with technical support in the first quarter of 2014.
When implemented, OSv will not have a long configuration, tuning or patching process. It will consist of a single configuration file that can be launched across a set of server nodes as part of a consistent virtual machine instance for scalability.
Cloudius will seek support from existing cloud software and NoSQL systems that can be "hardened" to work with OSv, such as Hadoop, MongoDB, and DataStax' version of Apache Cassandra.
Learn more about virtualization and cloud environments by attending the Interop conference track on Cloud Computing and Virtualization in New York from Sept. 30 to Oct. 4.