How to Add/Remove Yum Repositories

Red Hat Enterprise Linux, CentOS, Fedora and other Linux distributions based on RHEL all use YUM as a package management system to install, remove, and update software. Each distribution has its own main repository, but you can also install or remove third-party repositories whenever you like.
To add a YUM repository, type as root:
yum-config-manager –add-repo repository_url
For […]

How to Update Your OpenSSL Version to Fix Heartbleed Bug

Heartbleed, the highly publicized OpenSSL bug with the unfortunate name, has a lot of system administrators scurrying to fix the problem. If you have not heard about it by now, it is a security hole found in OpenSSL’s TLS heartbeat extension that a cyber criminal can use to reveal 64k of memory on a connected […]

How to Force Installation of Ubuntu Packages Kept Back

Ever so often, you might try to update your Ubuntu Server packages and find that certain ones are “kept back” during the upgrade process. These will often be kernel or other mission critical packages that do not get updated.
The reason some packages might get kept back is that some dependencies have been changed for them, […]

How Often Do You Reboot Your Server?

Once upon a time, it was conventional Unix server wisdom to reboot every month or so to make sure it was working correctly. These days many Linux system administrators boast about the number of days their servers have been up and running without interruption. BSD and other Unix-like OS users also claim similar uptimes, sometimes […]

How to Update Packages with Webmin

In the previous post, you learned how to install and remove software packages using Webmin’s graphical interface. Today, you will learn how to update individual packages and do a system-wide upgrade, all from within Webmin’s control panel.
Just like installing and removing packages, Webmin will rely on your package manager (APT, Yum, etc.) to update […]

Are There Benefits to Manually Installing Software?

Linux servers have a distinct advantage over most proprietary operating systems because of their extensive package management systems. Whether a server uses YUM or APT, it is much easier and faster to install and update software than using traditional manual installation methods. This raises the question: is it ever a good idea to install software […]

How to Fix APT Dependency Problems

APT is a package management system for Debian and other Linux distributions based on it, such as Ubuntu. For the most part, APT is easy to use for installing, removing, and updating packages.
With a normal APT install, using the apt-get command, a package will install without any problems. Installing a package in an APT repository […]

How to Reboot a Linux Server

Generally speaking, it is a good idea to avoid the need to reboot a dedicated server. The moment you do, your server will experience some amount of down time; hopefully only the amount of time it takes to shut down all processes and restart.
Therefore, it is a good idea to minimize reboots and schedule them […]

Short vs Long Time To Live (TTL) DNS

Time To Live is a term that refers to the amount of time that passes before a DNS zone is updated. If you are running your own DNS on your dedicated server, you may want to consider your TTL setting and how it affects your websites.
The old standard TTL setting for most DNS servers was […]

Working with APT on a Debian Server

Debian GNU/Linux and other OSes based on the free and open source operating system, such as Ubuntu, use a package management system called APT to install, update, and remove software.  APT is very powerful and easy to use.  You can access it from the command line via SSH, giving you full control over the software […]

Upgrading a Linux Server Kernel

On Linux-based operating system, the kernel (simply called Linux) is largely separate from the rest of the operating system. While drivers and hardware functionality are controlled by the kernel, applications and services are all separate. That means that you can safely upgrade portions your system and keep the same kernel.
On a dedicated server, […]

How to Force YUM to Exclude Certain Packages

YUM is the package management system for several Linux distributions, including three major server operating systems: Red Hat Enterprise Linux (RHEL), Fedora, and CentOS. Generally speaking, you can always safely perform updates to the latest software packages offered in the distribution repositories.
There are, however, instances when certain updates are acceptable but others may not […]