What Is KernelCare?

Tux the Penguin with Hotpatching (KernelCare)The concept of ‘Kernel hotpatching’, sometimes called live patching, was introduced to the Linux community around 2008. Soon after groups began developing differing implementations of the concept. KernelCare, one of the more popular implementations, was originally released in March 2014 by Cloud Linux, Inc. Continue reading “What Is KernelCare?”

Where Is My DNS Hosted?

From time to time, you’ll have to make changes to your DNS records. For example, if you change IP addresses, your DNS A records will change. You’ll also change DNS if you want to add SPF records to help email authentication. For these changes to work properly, it’s vital to know where DNS is hosted. Continue reading “Where Is My DNS Hosted?”

How to Install Git on Ubuntu 15.04

Introduction

Git is an open source, distributed version control system (VCS). It’s commonly used for source code management (SCM), with sites like GitHub offering a social coding experience, and popular projects such as Perl, Ruby on Rails, and the Linux kernel using it.

Pre-Flight Check

  • These instructions are intended for installing Git on Ubuntu 15.04.
  • I’ll be working from a Liquid Web Core Managed Ubuntu 15.04 server, and I’ll be logged in as root.

Continue reading “How to Install Git on Ubuntu 15.04”

How to Install and Configure Git on Fedora 22

Introduction

Git is a widely adopted, distributed version control system (VCS) and open source. It’s commonly used for source code management (SCM), with sites like GitHub offering a social coding experience, and popular projects such as Perl, Ruby on Rails, and the Linux kernel using it.

Pre-Flight Check

  • These instructions are intended for installing Git on Fedora 22.
  • I’ll be working from a Liquid Web Self Managed Fedora 22 server, and I’ll be logged in as root.

Continue reading “How to Install and Configure Git on Fedora 22”

View the Selected MySQL Database on Linux via Command Line

Pre-Flight Check

  • These instructions are intended for viewing the selected MySQL database via the command line.
  • I’ll be working from a Liquid Web Core Managed CentOS 7 server, and I’ll be logged in as root.

Continue reading “View the Selected MySQL Database on Linux via Command Line”

7 Extremely Useful Linux Commands for Beginners

#1: ls : What’s in this directory?

The command ls stands for list directory contents. And, cleverly, it will do just that: list a directory’s contents! Using it with -F will give a list of the directories contents, and denote items that are other directories with a trailing /.

ls -F

On my server returns:

allthethings.txt important.doc Indominus/ Misc/ probs.xls Red Wings/ Spreadsheets/ Work/

In the above case, allthethings.txt, garbage.file, important.doc, and probs.xls are files, and Indominus, Misc, Red Wings, Spreadsheets, and Work, each with the trailing /, are directories!

There are many other options, or switches, such as -F that can be used with ls for improved results. For example:

ls -lFa

Returns:

dr-xr-x---. 10 root root 4096 Apr 17 12:01 .
drwxr-xr-x. 19 root root 4096 Apr 14 12:45 ..
-rw-r--r-- 1 root root 0 Apr 17 12:00 allthethings.txt
-rw------- 1 root root 483 Apr 14 12:45 .bash_history
-rw-r--r--. 1 root root 18 Dec 28 2013 .bash_logout
-rw-r--r--. 1 root root 176 Dec 28 2013 .bash_profile
-rw-r--r--. 1 root root 361 Jan 1 01:24 .bashrc
drwxr-xr-x 3 root root 4096 Jan 1 01:25 .cache/
drwxr-xr-x 3 root root 4096 Jan 1 01:25 .config/
-rw-r--r--. 1 root root 100 Dec 28 2013 .cshrc
-rw-r--r-- 1 root root 0 Apr 17 12:01 garbage.file
-rw-r--r-- 1 root root 0 Apr 17 11:58 important.doc
drwxr-xr-x 2 root root 4096 Apr 17 11:59 Indominus/
drwxr-xr-x 2 root root 4096 Apr 17 11:57 Misc/
-rw------- 1 root root 42 Apr 14 12:44 .my.cnf
-rw-r--r-- 1 root root 0 Apr 17 12:00 probs.xls
drwxr-xr-x 2 root root 4096 Apr 17 11:57 Red Wings/
-rw------- 1 root root 1024 Jan 1 01:22 .rnd
drwxr-xr-x 2 root root 4096 Apr 17 11:56 Spreadsheets/
drw------- 2 root root 4096 Apr 14 12:42 .ssh/
-rw-r--r--. 1 root root 129 Dec 28 2013 .tcshrc
drwxr-xr-x 2 root root 4096 Apr 17 11:57 Work/

In the above case two switches are added: -l and -a. The -l uses the long listing format, and the -a switch lists all of the files, including hidden files.

Each column contains an important bit of information:

Column | Information | Example

  • 1 | Permissions | drwxr-xr-x
  • 2 | # of Hard Links | 2
  • 3 | User That Owns File or Directory | root
  • 4 | Group for File or Directory | root
  • 5 | File Size | 4096
  • 6 | Timestamp | Apr 17 11:59
  • 7 | Filename | Indominus/

Continue reading “7 Extremely Useful Linux Commands for Beginners”

How to Remove (Delete) a User on Ubuntu 14.04 LTS

Users via Command Line 101: Basic User Interaction
I. How to Add a User and Grant Root Privileges on Ubuntu 14.04 LTS
II. How to Remove (Delete) a User on Ubuntu 14.04 LTS

Pre-Flight Check

  • These instructions are intended specifically for removing a user on Ubuntu 14.04 LTS.
  • I’ll be working from a Liquid Web Core Managed Ubuntu 14.04 LTS server, and I’ll be logged in as root.

Continue reading “How to Remove (Delete) a User on Ubuntu 14.04 LTS”