Make Better Decisions for Your Businesses with Data Visualization

Header In today’s time, data visualization has become a significant part of the success story of an organization. With the help of right techniques, visualizing data can reveal insights which the management staff can use in their decision-making in order to make sound data-driven decisions. Mapping software is among the robust data visualization tools that you can avail today. With maps, you can find stories, trends, and insights that cannot be found in spreadsheets. » Read more

Vim Tutorial for Beginners: vimtutor

There are many Vim tutorials and Vim tips on the Web. However, I find the vimtutor provides the best tutorial among those so far as I found on the Web while the vimtutor seems usually reachable from a terminal which is not obviously known to Vim beginners who are usually Linux beginners too. This page shows the content of the Vim tutorial from the command vimtutor in a web page which is especially easier for Vim beginners to get and learn. » Read more

x-data-plane feature in QEMU/KVM

Abstract In systems, sometimes, we use one global lock to keep synchronization among different threads. This principle also happens in QEMU/KVM (http://wiki.qemu.org/Main_Page) system. However, this may cause lock contention problem. The performance/scalability of whole system will be decreased. In order to solve this problem in QEMU/KVM, x-data-plane feature is designed/implemented, which the high-level idea is “I/O requests are handled by dedicated IOThread rather than QEMU main loop threads so that it will not have lock contention among I/O threads and other QEMU main loop threads”. » Read more

Filter Salutation in Microsoft Dynamics CRM

CRM
In this tutorial, Microsoft Dynamics CRM India experts will teach you how to filter salutation based on Gender field in MS CRM. You can follow the step-by-step guide shared in this post to avail the results. Description- According to the requirement we need to filter salutation based on gender in contact entity. For this we need to create two new field having Datatype(option set). » Read more

How migration thread works inside of Linux Kernel

Abstract In computer systems, resources have to be balanced so that the performance will be better based on the same hardware. In Linux Kernel system, we will see some migration kernel threads running as daemons to do this kind of jobs as follows. In this article, we will discuss how Linux Kernel balances its hardware/software resources (NOTE: this article is based on Linux Kernel 4.7 and other versions may have some differences). » Read more

How sched_setaffinity works inside of Linux Kernel

Abstract Sometimes, we may want to migrate one process/thread to one specific CPU for some specific purpose. In the Unix/Linux systems, you may choose sched_setaffinity to finish this job. This article will help you to understand how sched_setaffinity (or other APIs like pthread_setaffinity_np in user-space) works internal Linux kernel. Details -- sched_setaffinity(pid_t pid, const struct cpumask *in_mask) --- __set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask, bool check) ---- stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) ----- migration_cpu_stop(void *data) ------ __migrate_task(struct rq *rq, struct task_struct *p, int dest_cpu) ------- move_queued_task(struct rq *rq, struct task_struct *p, int new_cpu) -------- enqueue_task(struct rq *rq, struct task_struct *p, int flags) --------- returns the new run queue of destination CPU Above character steps give a workflow of how sched_setaffinity works (how it migrates one process/thread from the run queue of source CPU to the run queue of destination CPU). » Read more

Essential Gnome Shell Extensions for Gnome 3 Users

Gnome Shell has a clean design. But many users want to get more from the desktop environment. Gnome 3’s extension system can help users customize the Gnome Shell’s look greatly. In this post, we summarize 6 extensions we considered essential to make Gnome Shell great. AlternateTab ∞ Make Alt-Tab “classic” instead of grouping windows by application. It substitutes Alt-Tab with a window based switcher. » Read more

How to Install 32-bit Wine 1.8 on CentOS 7

Since version 7, RHEL has only x86-64 versions. The same thing happens to CentOS 7. In CentOS 7/EPEL, there is only package for Wine x86-64. However, many Windows .exe files are 32-bit. Even there are 64-bit versions for some software, their installation file is 32-bit. And for some certain software such as Office 2007, 32-bit wine is preferred. In this post, we will check how to install 32-bit Wine 1.8 on CentOS 7. » Read more

Additional Repositories for CentOS Linux

CentOS is a super solid Linux distro. However, its default repository’s packages are limited compared to Fedora. Even Fedora needs some additional repositories to have software packages for daily usage, such as MPlayer, ffmpeg. Fortunately, some community maintained repositories provides these software. In this post, we introduce theses additional common repositories and how to install them into CentOS. For the installation method, we use CentOS 7 as an example. » Read more

How to Change Systemd Boot Target on Linux

Many Linux distros, such as RHEL/CentOS 7, Fedora, Ubuntu 16, are now using systemd instead of init as the init system. It is common for Linux users to set Linux to boot to “GUI” or “Text” mode. The old way of changing ‘/etc/inittab’ for choosing Linux runlevels is not working for sytemd. This post will introduce the way for systemd systems to select the “runlevels”. » Read more

How to Change Linux Account Password Through SSH: A Beginners’ Tutorial

People are sometimes given access to Linux/Unix and asked to change their initial passwords. But for beginners, changing a Linux/Unix password is not an easy task, especially when there is only SSH log on allowed to the Linux/Unix server. This post introduces how to change password of user USER on host HOST remotely using SSH. linux-passwd.png Steps are as follows. Note: you will need to replace HOST and USER with the actual username and hostname you are using. » Read more

How to Force Linux to Unmount a Filesystem Reporting “device is busy”

Linux may report “device is busy” when we try to umount a filesystem. This behavior is reasonable as it can help us avoid data loss by disallowing unmouting a filesystem when it is being used. But for situations when we are sure there is something wrong happened or we care not data lost such as a NFS mounting failed because that the NFS server is dead and will never be back. » Read more

How to Disable and Enable Laptop Keyboard in Linux

Attaching a USB keyboard to a laptop is common when using a laptop because a normal keyboard may provide a more convenient typing experience. The laptop keyboard is not used in these situations. However, the laptop keyboard may still be touched by accident. In this post, we will discuss how to disable and enable the laptop keyboard in Linux. I will also provide scripts ready for you to directly use them for disabling/enabling the laptop keyboard. » Read more

How to Get Bash Script’s Own Path

Bash script may need to get its own path. In normal Bash script, $0 is the path to the script. However, when a script is sourced, such as . a.sh, a.sh‘s $0 does not give a.sh while the caller’s name. How to reliably get a bash script’s own path no matter whether the Bash script is executed or sourced is introduced in this post. » Read more

How to Set the Static IP Address Using CLI in Fedora/CentOS Linux

How to set the static IP address for CentOS 7/Fedora 22+ is introduced in this post. Here, we assume the Linux is using NetworkManager to manage the network. All steps are done as root. Find the interface you want to set the address ∞ Command ifconfig -a lists all interfaces. Find the interface name to set, such as enp2s0. datacenter-servers.jpg Edit the interface’s configuration file ∞ For interface NAME, the configuration file is stored in /etc/sysconfig/network-scripts/ifcfg-NAME. » Read more

How to Add Google to Firefox in Linux Mint as Default Search Engine

In Firefox on Linux Mint, Google is not in the default list of search engines. Linux Mint has its criteria for adding search engines while Google seems not in those suggested by Linux Mint because “Amongst commercial search engines, only the ones which share with Linux Mint the revenue Linux Mint users generate for them are included by default” while Google seems not share revenue with Linux Mint. » Read more