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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).

How to backup and restore a partition table on Linux

Is it possible to just backup my Linux partition table and restore it when required? How do I restore partition table if it get deleted by mistake on Linux operating system? How do I backup and restore a GPT partition table on Linux?
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How To Read CPUID Instruction For Each CPU on Linux With x86info and cpuid Commands

Is there a CPU-Z like a freeware/open source software that detects the central processing unit (CPU) of a modern personal computer in Linux operating system? How can I get detailed information about the CPU(s) gathered from the CPUID instruction, including the exact model of CPU(s) on Linux operating system?
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How to find out AES-NI (Advanced Encryption) Enabled on Linux System

The Intel Advanced Encryption Standard (AES) or New Instructions (AES-NI) engine enables extremely fast hardware encryption and decryption for openssl, ssh, vpn, Linux/Unix/OSX full disk encryption and more. How do I check support for Intel or AMD AES-NI is loaded in my running Linux in my Linux based system including openssl?
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How to summarize detailed system resource usage for given command on a Linux or Unix

How do I determine the system resource usage during of execution of a particular command on a Linux, OS X Unix, BSD and Unix-like operating system?
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How To See Characteristics of File Systems on Linux or Unix

How do I display the characteristics of file systems such as inodes, blocks, block size, file system name, state, lifetime writes, fsck status and more on Linux or Unix-like operating system?
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How to Change a USER and GROUP ID on Linux For All Owned Files

I would like to know how to change a UID (USER ID)/GID (GROUP ID) and all belonging files on Linux operating system. Say, I want to change UID from 1005 to 2005 and GID from 1005 to 2005 on Linux. How do I make such change for belonging files and directories?
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How To Wakeup Backup Nas Server and Mirror Files Using Rsync in Linux

I‘ve a critical data stored on my small home server. I backup my Desktop, Laptop and a remote VPS server to my home nas server powered by Debian Linux using rsnapshot backup utility. In the event that my main nas server has a hardware (hard disk failure) problem, having mirrored files provides some sort of peace of mind. How do I mirror /backups/personal (total 100GB and growing everyday) to a secondary nas Linux server located in my network?
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How to Set Locales (i18n) On a Linux or Unix

What is a “locale” on a Linux operating system? How do I set or get locals (i18n) values on a Linux operating system?
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How To SSH Run Multiple Command On Remote Machine And Exit Safely

I have a backup sync program on local server. I have an ssh password less login set up, and I can run commands on an external server in bash script doing:

ssh root@server2 "sync; sync; /sbin/shutdown -h now"

How do I run multiple commands in bash on a remote Unix or Linux server? What is the best way to SSH in and run various unix commands in a bash shell?
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How To Install Speedtest-cli On a CentOS / RHEL / Scientific / Fedora Linux To Check Internet Speed

I do not want to use Adobe flash based speed testing site due to security concern on my desktop. How do I install Speedtest-cli on a CentOS Linux or Fedora Linux or Red Hat Enterise Linux (RHEL) for checking the Internet speed?
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