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CentOS Howtos and Tutorials

Centos Linux tutorial for beginners and advanced users with special focus on security, firewall, web, mail, file and proxy servers in an enterprise environment (rss feed).

Linux Change Disk Label Name on EXT2 / EXT3 / EXT4 File Systems

How can I modify partition labels on a Linux operating systems? How to change disk name on the ext4 file system on a Ubuntu Linux using command line?
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Ubuntu Linux: Edit and Open Files That Require Administrator Privileges

There are certain files in Ubuntu Linux (or Unix-like systems) that only root user access or edit. How can I edit and/or open files that requires admin (root) access on a Ubuntu Linux?
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Bash: Reissue And Repeat A Long Command Without Retyping It on a Linux, OS X & Unix

I‘m a new Ubuntu Linux user. In Linux, Apple OS X or Unix-like systems, how do I reissue or repeat a long command without retying it?
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How To Patch and Protect Linux Server Against the Glibc GHOST Vulnerability # CVE-2015-0235

A very serious security problem has been found in the GNU C Library (Glibc) called GHOST. How can I fix GHOST vulnerability and protect my Linux server against the attack? How do I verify that my server has been fixed against the Glibc GHOST vulnerability?
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How To Change Timezone on a CentOS 6 and 7

I set my time zone to ‘America/New_York’ on a CentOS Linux 7 server. I want to see date and time in my timezone in log files. How can I change the current timezone from ‘America/New_York’ to ‘America/Chicago’ using command line?
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How to Run and Execute Command When I Log Out Of Linux Session?

I‘m using CentOS 7 server. I need to run a command when I logout using ssh or bash shell. So in Linux and Unix-like systems, how can I run a command to execute when I log out my session?
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How To Extract a Tar Files To a Different Directory on a Linux/Unix-like Systems

I want to extract tar file to specific directory called /tmp/data. How can I extract a tar archive to a different directory using tar command on a Linux or Unix-like systems?
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CentOS / RHEL 7 Restart / Stop / Start Networking Command

I recently installed CentOS Linux version 7 or Red Hat Enterprise Linux version 7. How can I restart networking service using command line options? How can I start / stop and restart networking service on a CentOS/RHEL 7 based system?
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How To Install EPEL Repo on a CentOS and RHEL 7.x

How do I install the extra repositories such as Fedora EPEL repo on a Red Hat Enterprise Linux server version 7.x or CentOS Linux server version 7.x?
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Connect To Amazon AWS EC2 Instance From a CentOS / RHEL Using SSH Client

I have created/launched Amazon Machine Image (AMI) instance powered by a CentOS/RHEL/Red Hat Enterprise Linux. How can I connect to my instance using OpenSSH Linux/Unix/OSX ssh client?
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