Virtualization and Cloud

Jonathan Gershater

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Top Stories by Jonathan Gershater

When you host applications in the public cloud, you assume partial responsibility for securing the application. The cloud provider, for example Amazon Web Services (AWS), secures the physical data center (with locked badge entry doors, fences, guards etc) in addition to securing the physical network with perimeter firewalls. This is no significant change from how you secure your corporate datacenter. Just like you enhance the security of physical and virtual servers in your datacenter with host-based firewalls (ip tables, Windows firewall), anti-virus and intrusion detection, so you must protect your public cloud servers (in AWS parlance - "instances") with similar security measures. This is the joint or shared security responsibility - AWS secures the physical datacenter and firewalls the network; you the AWS customer secures each instance and its application with... (more)

The Fundamental Flaw with LinkedIn Connections

Assumption A first-degree direct LinkedIn connection implies that the two parties know each well. Problem Using this assumption, two unconnected LinkedIn users attempt to connect via an intermediary. What often happens is that the first degree connections are in fact very weak connections, and thus of no use to the third party attempting to connect via the intermediary. Example I log into LinkedIn and would like an introduction to Brent. I view Brent's profile and notice that his first degree connection, Brian, is also a first degree connection with me. So I ask Brian for an int... (more)

Examining Excellent Eucalyptus

Eucalyptus is an open source Infrastructure as a Service cloud offering. What is unique about Eucalyptus is that it is compatible with Amazon AWS APIs. This means that you can: Use Eucalyptus commands to manage Amazon or Eucalyptus instances. Freely move instances between a Eucalyptus private cloud and the Amazon Public cloud to create a hybrid cloud. Eucalyptus leverages operating system virtualization, such as KVM or XEN, to achieve isolation between applications and stacks. Operating system virtualization dedicates CPU and RAM to systems and applications such that they don't ... (more)

A Comparison Between OpenStack and VMware vCloud IaaS Offerings

I previously wrote a review of  the Microsoft Azure public cloud and included a comparison between Azure and AWS (Amazon Web Services) and will now compare OpenStack and VMware vCloud. For a review of IaaS (Infrastructure as a Service) see my blog post and video. This table provides a simple and high level comparison of OpenStack and vCloud. Feature OpenStack VMware vCloud Virtualization layer Type 2 virtualization - Libvirt layered on top of Linux. Supports various hypervisors: XEN, KVM, HyperV... Type 1 virtualization - bare metal; vSphere hypervisor only. Management Open API... (more)

Cloud Computing Easily Understood - IaaS

Infrastructure as a Service is one of the three delivery methods of cloud computing (the other two are Platform as a Service and Software as a Service). Users of IaaS have the expertise to maintain operating systems and applications, but don't wish to purchase server, storage and networking hardware and a datacenter to house the hardware. The cloud provider provides these services from a shared pool. The cloud user will then use the virtual machines to fulfill their computing requirements and may install their own operating system and will install their own applications on the v... (more)