World IPv6 launched today (6 June 2012)

Today (6 June 2012) is the world launching day for IPv6.

To recap, I wrote about the exhaustion of IPv4 last year. The address space used by the current version of the Internet protocol, IPv4, has already run out. Without action, we risk increased costs and limited functionality online for Internet users everywhere, in addition to curtailing the Internet’s growth of a platform for innovation and economic development. The only long-term solution to this problem is adoption of IPv6, which provides a practically unlimited number of addresses.

Now, major Internet service providers (ISPs), home networking equipment manufacturers, and web companies around the world are finally coming together to permanently enable IPv6 for their products and services by today (6 June 2012).

This marks the largest industry commitment to and deployment of IPv6 in the history of the Internet, with the ultimate aim to eventually replace the current IPv4.

Well, due to its vast usage and long time existance, IPv4 won't be replaced within a few years, and will co-exist with the new IPv6 for a lengthy transition period.

Meanwhile, for end users like you and me, whether it is IPv4 or IPv6 should be pretty transparent to us, as we are more adopted to the more human-readable domain names translated from the IP addresses.

In virtualization, use as few vCPU as possible for optimal CPU performance

Nowadays, virtualizing a physical server into several virtual servers is a common practice. In fact, the Infrastructure-as-a-Service (IaaS) model of Cloud Computing is based on virtualization too.

Unlike physical server running on physical CPU, whereby the common sense is more CPU (or CPU core) is better, in a virtualized environment, it is often a best practice to configure as few virtual CPU (vCPU) as possible to the virtual server.

In most cases, if 1 vCPU is sufficient, it is advisible to configure the virtual server to use 1 vCPU instead of more.

This is because:

• Each vCPU will consume some physical CPU resource even if it is in idle state.
• Unused vCPUs still consume timer interrupts unless the guest OS kernel is configured with the NO_HZ "tickless timer" option (a feature available in the latest Linux 2.6 kernel).
• The more vCPUs a virtual machine has, the more interrupts it requires.
• Maintaining a consistent memory view among multiple vCPUs can also consume additional resources, both in the guest OS and the host.
• Some older guest OS execute idle loops on unused vCPUs, thereby consuming
  resources that might otherwise be available for other uses.
• The guest scheduler might migrate a single-threaded workload amongst multiple vCPUs, thereby
  losing cache locality.
• In SMP guests the guest OS can migrate processes from one vCPU to another. This migration can incur a small CPU overhead.

In addition, it is a good practice to disable screen savers and Window animations in virtual machines. On Linux, if using an X server is not required, disable it. This is because screen savers, animations, and X servers all consume extra physical CPU resources, potentially affecting consolidation ratios and the performance of other virtual machines.

Reference: Performance Best Prictice for VMWare vSphere 5.0

3 questions to ask yourself before venturing into a new business

Are you planning to be entrepreneur to start your own business?

I have just learnt that there are 3 important questions you must ask yourself and sincerely find out your answers, because these are the crucial factors that will affect the success rate of a new business venture.

The 3 questions are:

• How likely will your targetted customers be really willing to take out the money from their pocket and pay for it?
• How big is the profit margin?
• What make you remarkable from others?

Basically, these 3 questions will test the feasibility of your business in terms of acceptability, profitability and sustainability.

You need to get the actual feedback from the real market by doing a lot of observation, conversation and testing.