Archive for the 'Operating Systems' Category

How To Install Docker on Ubuntu 16

Docker is a popular option for “virtual appliances” nowadays. Docker website defines the “Docker” moniker as a software containerization platform that is more flexible than traditional virtual machines since it virtualizes the operating system instead of the hardware. This means that Docker can further isolate the resources by enabling multiple Docker containers running on an operating system. If the operating system itself is running on a virtual machine either via full virtualization (bare metal) or paravirtualization, we will have a good example of IT infrastructure transformation from asset-ownership model into cloud-lease model (my related paper about such transformation can be read here). Continue reading

Maven Tutorial for Beginners: Installation and Configuration

maven_windowsMaven installation on Windows is very straightforward. Nonetheless, this post will provide sufficient elaboration to ensure a smooth installation. Following the installation, some configuration and testing tasks may need to be completed prior to creating the first Maven project.

A prerequisite for Maven installation is Java JDK. If you have not installed the Java SDK, you can refer to the installation procedure explained in this post.

The installation and configuration steps are executed in order as follows:

1. Download Maven zip package from the download page

Maven download page URL is
In this post, we will install and configure Maven 3.2.3. It can be anticipated that the installation procedure of the newer version of Maven will be quite similar with the one explained in this article.

2. Extract the zip into an installation directory of preference.

In this article, the directory contained in the extracted zip package is moved into “D:\Devs\DevHome\Maven\Bundle\apache-maven-3.2.3”. There is no strict rule regarding the installation directory. You can put the Maven directory in any directory of your choice. Continue reading

How to Install Java SDK on Windows

java_windows_sA lot of Java-based development tools require Java SDK as the dependency. This post will provide the guide on how to install Java SDK from Oracle on Windows, especially Windows 7. An additional configuration step is also included so that Java will be immediately ready for use by dependent applications.

Java SDK installation on Windows is apparently very straightforward. Oracle already provides a page explaining the Java SDK installation steps. This post focuses on step-by-step guide with necessary snapshot images to deliver better clarity on the installation process.

Java SDK Installation

1. Download Java SDK from the download page

Java SDK download page URL is

Oracle has released Java JDK 8 that provides improvement over the previous Java JDK 7. However, in this post we will choose Java JDK 7 since some popular libraries that we will use later may have not officially supported Java 8. To download JDK 7, click JDK download button from the Java SE 7uXX section and choose the binary version to download (32-bit or 64-bit). Continue reading

VMWare Customer Day 2010 Korea: Cloud Computing Adoption in Enterprises and vSphere 4.1

On Friday, September 10th, I attended VMWare Customer Day 2010 Korea, which was held at COEX Intercontinental Hotel, Seoul. Even though it has been a while past the event, I would like to share some notes worth sharing, combined with my personal thought about substantial content found in the talks I listened to during the event.

As the event title suggests, the talks mostly covered introductory concept about cloud computing and virtualization as well as some promotional materials about VMWare products. This is coherent with the majority of the audience who came from the enterprises: IT staffs, ISV representatives, and company delegates. Three sessions were arranged for the whole event. The first session was a talk from Mike Sumner, the VMWare Asia Pacific SE Director. He talked about customer journey to IT as a service by riding the cloud and harnessing virtualization. Second talk about VMWare case studies was presented by Lee Mun-hyong, the Director of Channel and Alliance, VMWare Korea. The last session was delivered by Lee-Hyo, the head of VMWare Korea. He explained about vSphere 4.1 especially the new features in the release. The second and third session were presented in Korean so I only grabbed the general understanding and did not really grasp the details.

In his presentation, Mike talked about cloud computing as an emerging trend in the enterprise. He also explained key drivers and phases toward its adoption in the enterprises and an era of IT as a service powered by the cloud. He started with listing several IT challenges in the enterprise environment. The challenges he mentioned include the necessity to deliver more business value, the ability to move faster and stay ahead of the competitors, the competency to maintain secure and compliant environment, and the capability of maintaining a stable system. Legacy IT business model relies on infrastructure ownership and dedicated IT force. With the introduction of the cloud in the enterprise, CIO may consider the transformation from a pay-in-advanced system into a cloud-based, pay-as-you-go system.
Continue reading

Fedora Quick Tip: Resolving Permission Denied Issues in HTTP and FTP services with getsebool and setsebool

If you are running Fedora Linux as a server, one issue you frequently encounter is strange permission denied error message triggered when you are accessing one of the available network services run on the server. There are a lot of network services to mention, but HTTP and FTP are two good examples of such services. Assume you are trying to access FTP server on your Fedora box. You type the IP address of the server and then supply the username and password. Voila!!! You thought you would be immediately logged in. But instead of seeing the files in your home folder, you are shown an error message. The error message may vary, from something like “Login incorrect for user blah” displayed by Midnight Commander, “500 OOPS: cannot change directory: /home/blah” from Total Commander, to other error messages shown by different FTP client programs.

If you are 100% sure that you supply the correct user and password information, why couldn’t you get in? Let us assume that you have root access to the server so that you can remotely troubleshoot from the console. This post will give some guide on how you can solve this problem based on common configurations of a Fedora server.
Continue reading