In the previous post, we explained how to check your Linux server for the highly publicized Shellshock vulnerability in Bash. Fortunately, most, if not all, major Linux distributions have already uploaded the fix into their package management repositories. All you have to do is install the latest version. Unfortunately, there is some evidence to suggest […]
The hosting world has been hit with yet another highly publicized server vulnerability. This one affects the ubiquitous shell program GNU Bash and is referred to as Shellshock. Most Linux, BSD and Mac OS X operating systems and variants use Bash or derivatives of it. All Bash versions between versions 1.14 and 4.3 are […]
Netcraft publishes a list of the web’s most widely used web server software every month. Here is a brief look at each of those top web servers and what they can do.
Microsoft IIS (37% market share) – Microsoft Internet Information Services is the web server designed specifically for Microsoft Windows Server operating […]
Systemd has gradually made a name for itself in the Linux world and is or will eventually be the default service management system for a number of major Linux distributions. Those accustomed to the old init systems will not find Systemd to be horribly complex, but it does feature some significantly different approaches to service […]
One of your best weapons in the fight for server security is strong password management. Using the password policies you set in Linux, you enforce strong passwords, require password renewals and many other effective security measures.
First, you should install the cracklib module for PAM. Cracklib tests password strength. If you are using RHEL, CentOS or […]
As you enter the world of server management, you are likely going to encounter free and open source software. Even a Windows system administrator these days will likely have to at least run Linux in a virtual machine at some point. Therefore, having a little background knowledge on how Linux and other open source software […]
When you think of Mac OS X, you probably tend to think of various iTunes, graphic design, music production and other artsy activities. It is primarily a desktop operating system, but Apple does sell a server add-on for its OS. The question is: Is that server version useful for real-world server operations?
Some of the advantages […]
As we discussed in a previous post, Linux servers offer many different types of file systems, and every other server operating system also offers a choice of file systems. One type of file system you might encounter is called a journaling file system. What is it and how does it differ from a standard Linux […]
While learning to use a Linux or BSD dedicated server, you are likely to encounter the terms binary and source software packages. Depending on your actual operating system, it may use one, the other or both as default methods of software installation.
A source package is a file archive that contains the full source code of […]
Linux is the kernel for many free and open source operating systems. Windows is a proprietary and commercial operating system, but there are many other differences between the two. When you are choosing an OS to run on your server, it is important to know some of the technical differences as well.
1. Access – Linux […]
In our last post, we looked at 5 Linux commands (technically six) that are invaluable to any new system administrator. The following are a few more, some of which are critical to know.
cat – This is a unique program that allows you to combine multiple files or parts into a whole. It can also print […]
In the previous 3 posts, we have covered several Linux terms that you should know when getting started managing a Linux server. What follows are some actual commands that will help you as you begin your journey.
cd – Probably the command you will use most frequently, “cd” stands for “change directory”. From the command […]
Part of the learning curve of a new Linux server is learning all of the terminology. You might not be familiar with some of them even if you have experiencing working on other operating systems. In part 3, we will look at some more of these terms.
daemon – This is a program that is often […]
In part one, we looked at some of the important terms a new system administrator should know when starting work on a Linux server. These next terms are equally important and will help you along the way as you begin to learn more about your server.
man – This command, short for manual, gives you […]
A large percentage of the world’s servers run Linux, so it is a good idea to know some of the common terms you might encounter while using it. The following terms are a good starting point.
Command Line Interface (CLI) – On the server end, this is the main method of interfacing you will use to […]
Linux is the kernel for a variety of operating systems that power many of the world’s servers. Although the operating systems themselves are often commonly called Linux, the actual term refers specifically to this kernel and all of its parts. In addition to the components that are compiled into the kernel, Linux also supports modules […]
SSH (Secure Shell) is a powerful command-line tool that allows you to securely manage your dedicated server from a remote location. If you have more than one server, however, it can become tedious to have to SSH into each one and make identical changes.
Cluster SSH is a software utility that gives you […]
Linux distributions that use binary packages usually install kernel updates in separate directories from previous kernel versions. Therefore, it is possible to have several instances of Linux installed within the same system. This is a precaution that prevents you from overwriting your kernel with one that may not function the way you want, or at […]
Linux comes with a very powerful tool built into it. It is called the shell. Bash is one version of the shell that is very popular with Linux distributions. If you can learn even basic Bash scripting, you can simplify and automate a lot of tasks you would normally have to manually perform on your […]
Swappiness might sound silly, but it is actually a very useful parameter in the Linux kernel that determines how aggressively the kernel will use the swap partition. Linux is usually already well-optimized to use very little swap when physical memory is available. With the swappiness setting, you can increase or decrease this usage.
The default setting […]
If you have grown up using Microsoft Windows on your desktop or laptop, you are probably accustomed to the universal solution to most problems: reboot. When your screen freezes, reboot. If your system gets slow, reboot. That is the standard solution that even tech experts often dish out to common users. As a server administrator, […]
The time may come when you need to add additional storage to your Linux dedicated server. This might be to install a solid state drive, create new databases, back up data, expand your websites or even to add new virtual machines. Regardless of the reason, you would essentially use the same method to make Linux […]
Your dedicated server has lots of logs. Almost every service and program running on a Linux or Unix server has a log file associated with it that includes relevant information about processes, errors and warnings. Sifting through all of those logs can be a pain, especially if you need to review old logs or compare […]
Server and website security seems to be in the headlines often lately with news of government surveillance and the heartbleed exploit in SSL. More than ever, it is important that you have a strong password. If you need to change your password on your Linux dedicated server or virtual private server, this guide should help […]
A recent report indicates that 97 percent of the world’s top 500 supercomputers run Linux. That statistic seems unfathomable, as if no other operating system even exists or is even worth mentioning. Most of the remaining 3 percent are some other Unix variant, and Windows barely registers at all. The question one […]
We have previously illustrated how to compile a program with Make. In this brief guide, you will learn a little bit about building with CMake, a useful alternative found in many Linux distributions.
First, you should install CMake on your system, if it is not already present. On RHEL and CentOS, type:
Linux services or daemons are programs that typically start when the system boots and remain running in the background until the system shuts down. What follows are three distinct ways to manage services RHEL and CentOS servers.
1. chkconfig – You can use this simple command to show current services, enable them, disable them, […]
Encryption has become a highly requested feature on the web lately with all of the talk of government spying, heartbleed and general security concerns. While most discussion has centered around encrypting the transport of data (via SSL), you might also want your data encrypted on disk as well. On a Linux-based server, you can encrypt […]
In many cases, you may find yourself needing a particular file or directory in one location while it is actually stored in another. One solution to this in Linux and Unix operating systems is linking. There are two types of links: hard links and symbolic links.
Hard links are always associated with a specific piece of […]