Where Does Evolution Save Its Data and Configuration Files on Linux?

Evolution is a great personal information management tool that provides Email, address book and calendar tools. Evolution provides many enterprise friendly feature such as native support to Microsoft Exchange connectivity for Emails, address books and calendars. Evolution uses various ways including plain files and dconf configuration systems. This post will give an introduction to the common locations or paths where Evolution stores its data and configuration files in Linux. » Read more
We ever discussed fixing ports used by NFSv3 so that it can be easily exported to external networks. For NFSv4.1 or higher, things are much easier. The ports for mountd, statd, and lockd are not required in a pure NFSv4 environment. We have less ports to control or allow for connections. Only port 111 and 2049 need to be taken care of for NFSv4. » Read more

How to Adding Customized Content on a Receipt

This blog will explain about how to add a custom content in a Receipt which will be generated from MPOS in Microsoft Dynamics. Microsoft provides us with certain fields which can be put into the receipt. There are certain fields which a client will ask to show in the receipt. If the desired field is not available in the standard receipt designer, we have to customize it. » Read more

How does load balancing work inside of operating systems, Linux as an example

IntroductionContents1 Introduction2 Load Balance Stack Inside Kernel3 Conclusion and Future Work4 References Load balance is used to rebalance the whole system resources (eg, CPU, memory, etc) so that system performance, scalability (in terms of no matter how many processes contend) and usability (in terms of idle resources can be used up immediately) will be improved. In this article, I mainly present how load balance for CPU reosurces works inside operating systems like Linux Kernel (v4.7.4). » Read more

NET Core 2.1 Release: Feature To Expect in 2018

What surprises are awaiting the tech world with .NET Core 2.1 Release in 2018? Technology is one of the most dynamic spheres these days. Every single year you will find a new version of an existing software and .NET Core is not an exception. The intentions of these upgradation is to make online activities seamless, daily work hassle free and to bring the world within our easy reach. » Read more

A List of Common Software on Windows

Quick links to some useful software on Windows including Web browsers, Video/audio player and ssh/scpsftp/vnc tools for connecting to Linux. software photo ssh/scp/sftp/vnc for connecting to Linux ∞ For Linux users, it is sometimes unavoidably to use Windows. With Windows, the Linux users will need to connect to Linux for some tasks. Some general software are needed. The most common ones may be ssh/scp/sftp/vnc. » Read more

How to Implement Hibernate Envers in an Application

Hibernate Envers TechnologyContents1 Technology2 Implementing Hibernate Envers in an application3 Revisioning4 Hibernate Configuration Properties for Envers5 Usage of Hibernate Envers6 Reading Audited Entities7 Conditional Auditing8 Tracking entity names modified during revisions9 Conclusion Hibernate Envers is the frameworks for auditing entities. As the name suggests Hibernate Envers is developed on top of Hibernate, it will on Hibernate and Hibernate implemented JPA. » Read more

Deploying ASP.NET Core 2.0 MVC application to Azure Web apps using Visual Studio 2017

IntroductionContents1 Introduction2 Quick Overview3 Prerequisites4 Getting started with MVC Web Application5 Deploying to Azure Web Apps6 Verify on Azure Portal7 Modifying & Redeploying8 Conclusion In this tutorial, we will be learning as how to deploy .NET Core 2.0 MVC web application on Microsoft Public Cloud i.e. Microsoft Azure, using Microsoft Visual Studio 2017 v15.3 For novice Cloud developers, aspiring .NET / Cloud architects, and all other IT professionals associated with the .NET Core framework & Cloud computing, especially with Microsoft Azure, this tutorial will explain the importance and capabilities of newly released . » Read more

A Beginners’ Guide to x86-64 Instruction Encoding

The encoding of x86 and x86-64 instructions is well documented in Intel or AMD’s manuals. However, they are not quite easy for beginners to start with to learn encoding of the x86-64 instructions. In this post, I will give a list of useful manuals for understanding and studying the x86-64 instruction encoding, a brief introduction and an example to help you get started with the formats and encodings of the x86-64 instructions. » Read more

How to force a metadata checkpointing in HDFS

The metadata checkpointing in HDFS is done by the Secondary NameNode to merge the fsimage and the edits log files periodically and keep edits log size within a limit. For various reasons, the checkpointing by the Secondary NameNode may fail. For one example, HDFS SecondaraNameNode log shows errors in its log as follows. 2017-08-06 10:54:14,488 ERROR org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode: Exception in doCheckpoint java.io.IOException: Inconsistent checkpoint fields. » Read more

How To Debug Linux Kernel With Less Efforts

Introduction In general, if we want to debug Linux Kernel, there are lots of tools such as Linux Perf, Kprobe, BCC, Ktap, etc, and we can also write kernel modules, proc subsystems or system calls for some specific debugging aims. However, if we have to instrument kernel to achieve our goals, usually we would not like to pay more efforts like above solutions since we’d like to achieve our aims quickly and easily. » Read more

QEMU/KVM Network Mechanisms

Introduction As we know, network subsystems are important in computer systems since they are I/O systems and need to be optimized with many algorithms and skills. This article will introduce how QEMU/KVM [2] network part works. In order to put everything simple and easy to understand, we will begin with several examples and then understand how it works internally. Examples In this example, we will use TAP device [1] as QEMU/KVM host network device driver and VirtIO driver will be used to send/receive network packets/data between Host OS and Guest OS. » Read more

I/O Microscopy: Tasks’ Disk I/O Information with High Accuracy

Abstract Most popular task monitor systems (such as top, iotop, proc, etc) can only get tasks’ disk I/O information like tasks’ I/O utilization percentage every seconds due to kernel timer/tick frequency and high time cost of system interfaces. This article presents I/O Microscopy, a new way to get tasks’ disk I/O information with high accuracy. Experiments show that I/O microscopy can filter out I/O intensive tasks effectively. » Read more

7 Common On Page SEO Mistakes You Are Making and You Should Not

With Google algorithm becoming more intelligent with each passing day, the margin for errors has significantly reduced over the past decade. Back in the day, you might get away with keyword stuffing but today, the same offense will strike off your website from Google search engine results. No one wants that, right. To save you from such a situation, here are ten common mistakes that most casual followers of the industry are making but should not. » Read more

How Easy Is It to Perform SEO?

The word “viral” has received a lot of attention over the last few years and is applied to different types of content to describe how quickly it has spread and gained popularity. Many times, you’ll hear people speak about their idea and how fast it will spread while assuming that it will “go viral”, but they never seem to understand how they’re going to make it go viral. » Read more

Call Forwarding for iPhone: How to Set up or Disable Call Forwarding in iOS

Call forwarding is useful if you are expected to be unavailable for receiving calls or lose cell phone coverage for some time. Call forwarding is not something that is "new" to modern phones. It is a feature which is invented in 1960s (the patent expired in 1980) of some telephone switching systems. But with iPhone/iOS, there is a convenient call forwarding feature in iOS for you to set up call forwarding to forward calls to a landline or other phone by its number or disable the call forwarding. » Read more

Reference: Special HTML Characters

HTML supports many characters/symbols such as mathematical symbols, and currency symbols. They are not present on a normal keyboard. And some of these characters may have special meanings for formatting text. To add such characters / symbols to an HTML text, you can use an HTML entity name or an entity number in decimal or hexadecimal. This post list many special Characters in HTML as a friendly reference. » Read more

Basic Knowledge of HTML and Canvas

From a small business owner, a blogger, a student or individual with a personal project, the need to create websites has never been more prominent. Having a basic understanding of HTML and canvas knowledge can be helpful, and it is simple to master. The thought of learning to code and programming may seem a long and daunting task, but some people may be surprised to know that it need not be as scary as it sounds. » Read more

How to Install Paravirtualized CentOS 7 DomU on Xen

This post introduces how to install a paravirtualized CentOS 7 DomU on Xen. The very common way of installing DomU does not work for CentOS 7. A little trick to set the repository and the network used by the VM should be used by adding a setting strings to the “extra=” field for this VM. Note that this tutorials was tested with CentOS 7.2 (1511). » Read more