DoubleCloud => Private Cloud + Public Cloud

There are a few metaphors that help explain what virtualization is. Some suggested virtualization is like people (virtual machines) sharing a bus (physical machine) for efficiency and consolidation.

While the bus sample well explains the benefit of consolidation. It does not explain well isolation. Here I make up a new one: a hypervisor is like a containership, and a virtual machine is like a container that is stacked on the ship.  Read more...

An operating system (OS) is a piece of software. It manages the computer hardware and provides common services for various applications. With the rise of cloud computing, people may wonder whether the OS is still relevant and what role it will play in the future cloud.

Key Components of OS

There are different flavors of operating systems: from real-time OS, desktop OS, all the way to a mainframe OS. The most recent OS is the Cloud OS.

In general, every OS has these common components:

• The kernel, which manages memory, processes, etc.
• Device drivers, which drive different hardware from different vendors.
• User interfaces, including command line shell and Window system.
• File system, which provides a hierarchical way to persist data.
• Security, which authenticates users and protects information.

Depending on the type of OS, you may miss something here or have something extra. For example, an embedded OS may not have a user interface and everything is controlled remotely. For the desktop OS, you may have extra commonly used applications such as a calculator, a calendar, a browser, and so on.

Squeezed Sandwich  Read more...