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)

Installing RDO Grizzly on Centos Using Packstack

OpenStack is easily installed using a package called Packstack. Redhat is one of the primary contributors to packstack and my install experience is similar to the installation of RDO, described here The procedure is quite simple: Install Redhat, Fedora or Centos on one or more x86 servers. I installed the minimal Centos installation on a Dell 1950 Install and configure NTP - network time protocol # yum install ntp # chkconfig ntpd on # ntpdate pool.ntp.org # /etc/init.d/ntpd start Install the Fedora repo for grizzly # yum install -y http://rdo.fedorapeople.org/openstack/opensta... (more)

Cloud Computing Easily Understood - SaaS

In prior blog posts, I described Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). To recap: If I use IaaS I get servers onto which I can load software and applications which I then maintain, though I don't need to maintain the hardware. I can customize the applications and software running on the servers, at will. If I use PaaS, I get a platform of ready to use web servers, application servers, databases etc. I write my own software application and host it at the PaaS provider. I maintain the software I write, but not the application servers, databases or ha... (more)

Brief Summary of IaaS, PaaS, SaaS

In this posting, I summarize my prior three posts on the three cloud computing offerings: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). I concentrate how the three offerings differ with respect to flexibility, maintenance and portability. One of the greatest challenges companies face when moving to the cloud is security. Thus I will devote an entire blog post in the future, to security concerns. Flexibility How much flexibility do you have with each offering? What can you change or modify within each cloud offering to suit you... (more)

High Availability, Fault Tolerance and Disaster Recovery in AWS

Amazon Web Services – Disaster Recovery, High Availability and Fault Tolerance Abbreviations used: AWS - Amazon Web Services AMI - Amazon Machine Instance DR - Disaster Recovery FT - Fault Tolerance HA - High Availability Non-technical introduction. High Availability and Fault Tolerance – the requirement that a computer application be seemlessly available to users without interruption, literally “no (or very little) fault will be tolerated”. In simple speak, this means that I am able to use a computer application even though in the background there may be outages, for example har... (more)