I/O Virtualization:
Decoupling a logical device from its physical implementation offers many compelling advantages.
The term virtual is heavily overloaded, evoking everything from virtual machines running in the cloud to avatars running across virtual worlds. Even within the narrowfigureer context of computer I/O, virtualization has a long, diverse history, exemplified by logical devices that are deliberately separate from their physical instantiations.
CTO Roundtable: Virtualization Part II:
When it comes to virtualization platforms, experts say focus first on the services to be delivered.
Last month we published Part I of a CTO Roundtable forum on virtualization. Sponsored by the ACM Professions Board, the roundtable features five experts on virtualization discussing the current state of the technology and how companies can use it most effectively. In this second and final installment, the participants address key issues such as choosing the most appropriate virtual machine platform, using virtualization to streamline desktop delivery, and using virtualization as an effective disaster-recovery mechanism.
Moving to the Edge: CTO Roundtable Overview:
An overview of the key issues addressed in ACM’s CTO Roundtable on network virtualization
The general IT community is just starting to digest how their world is changing with the advent of virtual machines and cloud computing. These new technologies promise to make applications more portable and raise the opportunity of more flexibility and efficiency in either on-premise or outsourced supporting infrastructure. Before taking advantage of these opportunities, however, data-center managers must have a better understanding of service infrastructure requirements than ever before. The CTO Roundtable on Network Virtualization focuses on how virtualization and clouds impact network service architectures, both in the ability to move legacy applications to more flexible and efficient virtualized environments and in what new functionality may become available.
Moving to the Edge: An ACM CTO Roundtable on Network Virtualization:
How will virtualization technologies affect network service architectures?
The general IT community is just beginning to digest how the advent of virtual machines and cloud computing is changing their world. These new technologies promise to make applications more portable and increase the opportunity for more flexibility and efficiency in both on-premises and outsourced support infrastructures. However, virtualization can break long-standing linkages between applications and their supporting physical devices. Before data-center managers can take advantage of these new opportunities, they must have a better understanding of service infrastructure requirements and their linkages to applications.
CTO Roundtable: Virtualization Part I:
CTOs from key players in the virtualization market examine current trends in virtualization and how IT managers can make the most effective use of it.
The topic of this forum is virtualization. When investing in virtualization technologies, IT managers need to know what is considered standard practice and what is considered too leading edge and risky for near-term deployment. For this forum we’ve assembled several leading experts on virtualization to discuss what those best practices should be. While the participants might not always agree with each other, we hope their insights will help IT managers navigate the virtualization landscape and make informed decisions on how best to use the technology.
Network Virtualization: Breaking the Performance Barrier:
Shared I/O in virtualization platforms has come a long way, but performance concerns remain.
The recent resurgence in popularity of virtualization has led to its use in a growing number of contexts, many of which require high-performance networking. Consider server consolidation, for example. The efficiency of network virtualization directly impacts the number of network servers that can effectively be consolidated onto a single physical machine. Unfortunately, modern network virtualization techniques incur significant overhead, which limits the achievable network performance. We need new network virtualization techniques to realize the full benefits of virtualization in network-intensive domains.
The Cost of Virtualization:
Software developers need to be aware of the compromises they face when using virtualization technology.
Virtualization can be implemented in many different ways. It can be done with and without hardware support. The virtualized operating system can be expected to be changed in preparation for virtualization, or it can be expected to work unchanged. Regardless, software developers must strive to meet the three goals of virtualization spelled out by Gerald Popek and Robert Goldberg: fidelity, performance, and safety.
Beyond Server Consolidation:
Server consolidation helps companies improve resource utilization, but virtualization can help in other ways, too.
Virtualization technology was developed in the late 1960s to make more efficient use of hardware. Hardware was expensive, and there was not that much available. Processing was largely outsourced to the few places that did have computers. On a single IBM System/360, one could run in parallel several environments that maintained full isolation and gave each of its customers the illusion of owning the hardware. Virtualization was time sharing implemented at a coarse-grained level, and isolation was the key achievement of the technology.
Meet the Virts:
Virtualization technology isn’t new, but it has matured a lot over the past 30 years.
When you dig into the details of supposedly overnight success stories, you frequently discover that they’ve actually been years in the making. Virtualization has been around for more than 30 years since the days when some of you were feeding stacks of punch cards into very physical machines yet in 2007 it tipped. VMware was the IPO sensation of the year; in November 2007 no fewer than four major operating system vendors (Microsoft, Oracle, Red Hat, and Sun) announced significant new virtualization capabilities; and among fashionable technologists it seems virtual has become the new black.
A Conversation with Jason Hoffman:
A systems scientist looks at virtualization, scalability, and Ruby on Rails.
Jason Hoffman has a Ph.D. in molecular pathology, but to him the transition between the biological sciences and his current role as CTO of Joyent was completely natural: "Fundamentally, what I’ve always been is a systems scientist, meaning that whether I was studying metabolism or diseases of metabolism or cancer or computer systems or anything else, a system is a system," says Hoffman. He draws on this broad systems background in the work he does at Joyent providing scalable infrastructure for Web applications.
The Virtualization Reality:
Are hypervisors the new foundation for system software?
A number of important challenges are associated with the deployment and configuration of contemporary computing infrastructure. Given the variety of operating systems and their many versions—including the often-specific configurations required to accommodate the wide range of popular applications—it has become quite a conundrum to establish and manage such systems.