LinuxConfig -

Installing A Django Development Environment on Ubuntu

September 22, 2016
by Nick Congleton

Django is easily the most popular web framework written in Python. It strikes a delicate balance between feature completeness and efficiency, including powerful features like automatic migration generation and a full-featured admin interface. Setting up a Django development environment in Ubuntu is fairly easy, and can be done in only a few steps.

Installing Virtualenv

It’s best to use a Python virtual environment when developing in a complex framework like Django, especially if you intend to work on multiple projects at once. It’s also probably a good idea to make sure that you have both versions of Python up to date.

$ sudo apt-get install virtualenv python python3

How to export/import VM to/from a backup file using command line on XenServer

Objective

The objective is to first export XenServer's virtual machine into a regular backup file and later import a new virtual machine from the previously generated backup file.

Requirements

Privileged access to XenServer's command line.

Difficulty

EASY

Instructions

Identify VM's UUID

We start by identifying a virtual machine we would lake to export to as a regular backup file. Run xe vm-list to list all available virtual machines and take a note of the virtual machine in question:

# xe vm-list
uuid ( RO)           : 7371124f-7d4d-66b7-cbc7-a98b1457543e
     name-label ( RW): Debian Jessie 8.5
    power-state ( RO): halted


uuid ( RO)           : bad8e456-df88-435d-ba12-3f0f6e54b2c6
     name-label ( RW): Control domain on host: xenserver
    power-state ( RO): running

How to take and restore VM snapshot using command line on XenServer

Objective

The objective is to create a new snapshot of a XenServer virtual machine and later restore from this snapshot.

Requirements

Privileged access to XenServer's command line.

Difficulty

EASY

Instructions

Identify VM's UUID

First, we need to identify a VM's UUID we wish to take a snapshot from. Use xe vm-list to list all available VM:

# xe vm-list
uuid ( RO)           : 7371124f-7d4d-66b7-cbc7-a98b1457543e
     name-label ( RW): Debian Jessie 8.5
    power-state ( RO): halted


uuid ( RO)           : bad8e456-df88-435d-ba12-3f0f6e54b2c6
     name-label ( RW): Control domain on host: xenserver
    power-state ( RO): running

How to rename VM ( virtual machine ) name label on XenServer

Objective

The objective is to set a new name label on a existing XenServer's VM ( virtual machine ).

Requirements

Privileged access to XenServer's command line as well as configured ISO image storage containing an ISO image of the Linux distribution you wish to install.

Difficulty

EASY

Instructions

Identify VM's UUID

In order to set/rename VM's name label we fisrt need to identify its UUID. List all VM's and take a note of a relevant UUID. Example:

# xe vm-list
uuid ( RO)           : bad8e456-df88-435d-ba12-3f0f6e54b2c6
     name-label ( RW): Control domain on host: xenserver
    power-state ( RO): running


uuid ( RO)           : 699dcb0c-e897-5bd4-30c1-ab1dd9a3ca4e
     name-label ( RW): Debian Jessie 8.0
    power-state ( RO): halted

How to install Discord on Linux

September 14, 2016
by Nick Congleton

In a relatively short time, Discord has become the favorite chat solution among gamers. That’s a fairly good thing. It’s easy to use and well supported across all platforms. Well, not quite. If you go to the Discord website at the time of writing this, there is one glaring omission from Discord’s list of available clients, Linux.

However, the Discord developers do plan on supporting Linux and have even released an experimental ‘canary’ version that you can install and use now. It’s definitely not perfect, but it does work fairly well, and, if you’re a gamer, why miss out?

Discord running on Ubuntu

Debian/Ubuntu

The Discord ‘canary’ release has actually been packaged for Debian based distributions. Users of Debian, Ubuntu, Mint, or any of their derivatives should have no problem simply downloading the package and installing it. First, pull the .deb from the Discord website.

$ wget https://discordapp.com/api/download/canary?platform=linux

Once it’s done downloading, just install it with dpkg.

$ sudo dpkg -i /path/to/discord-canary-0.0.8.deb

That’s it! You should be able to open up and use Discord. Plus, since it’ a Debian package, it should be easy to upgrade to future releases.
Read more ...

How to create a new virtual machine on XenServer using command line

September 8, 2016
by Lubos Rendek

Objective

Deployment of XenServer virtual machine using command line.

Requirements

Privileged access to XenServer's command line as well as configured ISO image storage containing an ISO image of the Linux distribution you wish to install.

Difficulty

MODERATE

Instructions

Deploy VM template and gather information

In this guide we will be creating a new Ubuntu Linux based virtual machine. However, the below procedure will fit any decent Linux distribution as along as it is supported by XenServer, meaning that the template for the Linux distribution you would like to install is part of the XenServer's repertoire. Let's first search XenServer's database for a template name.

In this case we are looking for Ubuntu 16.04:

# xe template-list | grep name-label | grep -i 16.04
          name-label ( RW): Ubuntu Xenial Xerus 16.04

How to rename VDI/Virtual disk on XenServer Linux

Objective

The Virtual Machine creation using template provisioner may spawn unnamed VDI disks. Usually, the VID description states Created by template provisioner at most. Example:

uuid ( RO)                : 093e128a-2632-43bd-bb45-8f864bc69d6f
          name-label ( RW): 0
    name-description ( RW): Created by template provisioner
             sr-uuid ( RO): 3ef7b35b-5d39-7414-0c91-bbb281b9a521
        virtual-size ( RO): 21474836480
            sharable ( RO): false
           read-only ( RO): false

The objective is to set a proper name and description to VDI disk.
Read more ...

How to reset the root password in RHEL7/CentOS7/Scientific Linux 7- based systems

September 8, 2016
by Rado Folwarczny

Objective

Resetting the root password in RHEL7/CentOS7/Scientific Linux 7

Requirements

RHEL7 / CentOS7 / Scientific Linux 7

Difficulty

MODERATE

Instructions

Things have changed in the RHEL7 world and so has the preferred way of resetting the root password. Although the old way of interrupting the boot process (init=/bin/bash) still works, it is no longer bulletproof and recommended. 'Systemd' uses 'rd.break' to interrupt the boot. Let's have a quick walk through the whole procedure.
Read more ...

Installing WINE

September 4, 2016
by Nick Congleton

Installing WINE

Since there are multiple available versions of WINE, there are different ways to install it as well. Of course, each distribution also packages and ships WINE differently, and most only ship one or two versions of it. Thankfully, there are third party repositories available, and, when all else fails, WINE can be compiled from source. Unless you’re running Gentoo, source should probably be the last resort, since it’s obviously harder to maintain, but it can work in cases where you want a custom WINE build that isn’t packaged for your distro.
Read more ...

Monitoring Temperatures and Voltages in Linux

September 2, 2016
by Nick Congleton

Introduction

The ability to monitor the temperatures of key components is important, whether you’re gaming, overclocking, or doing something more businesslike and running a critical server. Linux includes modules in the kernel that allow it to access onboard sensors within components. Though, that alone is not enough.

There is a program that does work in conjunction with those modules to display the readings of those sensors in the userspace. That program is lm_sensors. Lm_sensors allows users to get a readout of sensor readings in the command line and interfaces with several graphical front ends that make displaying temperatures in real time automatic and easy.

Installation

Lm_sensors is in nearly every distro’s repositories. In most cases, installation is as simple as a single command. Since it lm_sensors is a daemon, it will need to be started in all distributions, but the Debian based ones, which start it automatically.