Linux System Administration - Part 2

In this post, we are continuing with the commands that are used for Linux system administration. How to change the hostname 1) [For RedHat and Centos] Using a text editor open the file /etc/sysconfig/network and Modify the HOSTNAME= value to match your server’s new name <div id="crayon-69432b7201545338826610" class="crayon-syntax crayon-theme-powershell crayon-font-monaco crayon-os-pc print-yes notranslate" data-settings=" minimize scroll-mouseover" style=" margin-top: 12px; margin-bottom: 12px; font-size: 12px !important; line-height: 15px !important;"> <div class="crayon-toolbar" data-settings=" mouseover overlay hide delay" style="font-size: 12px !

A planet hotter than some of the stars

Astronomers have discovered a massive exoplanet, named KELT-9b, that is hotter than some of the stars. With a day-side temperature of more than 7,800 degrees F. (4,316 degrees C.), it is only about 2,000 degrees F. (about 1,000 degrees C.) cooler than our sun. This newly discovered planet is three times larger than Jupiter. It orbits a blue star, KELT-9, that is 650 light years away from the Earth. KELT-9 is more than twice as large, and nearly twice as hot, as our sun.

India’s heaviest and most powerful rocket launched

On June 5, 2017, the Indian Space Research Organisation (ISRO) launched its first Geosynchronous Satellite Launch Vehicle Mark III rocket from India’s Satish Dhawan Space Centre Sriharikota. It marked India’s heaviest and most powerful launch to date. The GSLV Mark III rocket was used for launching a massive communications satellite GSAT-19 into orbit. The rocket’s main and bigger cryogenic engine has been developed by space scientists here. The mission’s success enables India to launch four-tonne satellites on its own rocket instead of paying huge amounts of money to foreign space agencies to execute the operation.

Linux Commands for System Administration - Part 1

Linux System Administration involves procedures and tasks that are required to keep a computer system up and running and in usable order. Usually, it includes :

• installing new programs
• creating / deleting user accounts
• ensuring file system is not corrupted
• taking backups and restoring the backup when required
• monitor system resources, users, status of critical processes and file system usage
• starting and stopping the system
• configuring run levels, boot process, init, etc.

Let us take a look at the tasks and commands that are generally used by the system administrators.

• Monitoring the system

In order to check the health of a Linux machine, we can us commands such as :

1. w   – this command shows which users are logged on
2. uptime – shows how long the system has been running
3. iostat – shows CPU statistics

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w

10:07:51 up 23 min, 2 users, load average: 0.08, 0.11, 0.12 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT al tty8 :0 09:44 23:45 15.90s 0.12s cinnamon-sessio al pts/1 :0 10:05 3.00s 0.17s 0.65s gnome-terminal

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uptime

10:07:54 up 23 min, 2 users, load average: 0.07, 0.10, 0.12

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iostat

Linux 3.19.0-32-generic (al-T420) 17-06-06 x86_64 (4 CPU)

avg-cpu: %user %nice %system %iowait %steal %idle 3.19 0.02 0.91 0.34 0.00 95.54

Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 23.85 743.50 209.36 1067758 300672

• Process Management

The top command displays the status of the processes, their resource usage, etc. Apart from that,  commands like “ps -auxw”  and “pstree” will give detailed information about the processes running.  Also, the “kill” command can be used to stop a specific process using its PID (process id – which is a unique number associated with each process).

top command :

pstree command :

“ps -auxw” command :

“ps -ef” command :

Intel’s New Flagship Core i9 Processors Launched

Intel has officially released the new core i9 (Skylake-X) and Kaby Lake-X processors earlier this week as part of its Core-X family. Processors range from the “lowly” $242 Core i5-7640X to the monster Core i9-7980XE, which is priced at $1,999. The core i9 series provides huge performance gains, with Intel claiming up to 10 percent faster multi-threaded and 15 percent single-thread performance over its predecessor. The least expensive model in the Core i9 family is Core i9-7900X costs $999.

New Security Features of Linux Kernel 4.10

Linux Kernel 4.10, code-named Anniversary Edition, has been released by Linux Torvalds. This supports new hardware and also comes with many new features. The most significant improvement is the support for virtual GPU such as Intel GVT-g for KVM (KVMGT), which is a full GPU virtualization solution with mediated pass-through. As per Kernelnewbies, “The capability of running native graphics driver inside a VM, without hypervisor intervention in performance critical paths, achieves a good balance among performance, feature, and sharing capability.

Docker : Brief Introduction - Part 1

Docker has gained popularity among DevOps teams recently due to its efficient and straightforward usage of containerization technology. Let us take a brief look at Docker in this post. There will be few additional posts in continuation of this, where we will discuss few additional details. What is Docker ? Docker is a tool that automates the deployment of applications inside software containers. It is promoted by the company Docker, Inc.

Opera’s new release has built-in sidebars for WhatsApp, Telegram and Messenger

Opera has released a new version, code named ‘Reborn’, with provision to launch WhatsApp, Telegram and Facebook Messenger from the sidebar. The Norwegian browser maker (acquired by a Chinese tech company in 2016), has announced that the latest version of its browser is adopting some messaging features from Neon, an experimental version of Opera. The new features include built-in support for Facebook Messenger, Telegram, and WhatsApp in Opera 45. The chat window is available at the same browser window’s sidebar.

Surgeons Could Benefit from Microsoft HoloLens

Microsoft HoloLens, is a pair of mixed reality smartglasses developed and manufactured by Microsoft. HoloLens gained popularity for being one of the first computers running the Windows Mixed Reality platform under the Windows 10 operating system. Since the HoloLens was introduced, Microsoft has pitched it as both a gaming peripheral and a practical assistant in the workplace. Scopis, a company specializing in surgical navigation and medical augmented and mixed reality technologies, announced recently the launch of its newest development, the Holographic Navigation Platform for use in surgery.

New Android Malware Samples Found Every 10 Seconds

It is an open fact that Android is not the safest mobile platform. Its open nature, often gives room for vulnerabilities that can be exploited and compromise users’ security. G Data antivirus software firm has now discovered that the malware-infected applications are increasing at an alarming rate on Android mobile platform and at the current speed, 3.5 million new malware samples are expected to be discovered on the OS by the end of this year.