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Intermediate Linux / Unix System Administrator Tutorials

These tutorials assumes that you have strong understanding of Unix like operating systems and very comfortable with most aspects of the Unix/Linux operating system. Familiar with fundamental networking/distributed computing environments is required. ( rss feed )

Nginx: Allow All But Block Certain POST Request URLS For Selected Spammer IP Address/CIDR

I am a small business and ecom site owner. I also run a WordPress based blog to connect with my customers. However, I get too much spam from certain IPs and net-blocks. How do I block access to certain url(s) such as example.com/blog/wp-comments-post.php for selected IP address and CIDRs? How do I allow everyone including IP address 1.2.3.4 to access my blog but block IP address 1.2.3.4 accessing only example.com/blog/wp-comments-post.php? How do I block POST requests for selected IPs/CIDR on nginx?
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HowTo: Upgrade CentOS Linux 6.4/6.3/6.2/6.1/6.0 to v6.5

CentOS Linux v6.5 has been released and available via repos for immediate update. The new version includes several hundred bug fixes for, and enhancements to the Linux kernel. How do I upgrade from CentOS Linux version 6.0 / 6.1 / 6.2 / 6.3 or 6.4 to the latest version 6.5?
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WordPress MySql Statement To Delete All Pending Comments

I have over 1800+ pending comments and most of them are spams in WordPress based blog. How do I delete all (mass delete) the pending comments using sql statements?
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CentOS / RHEL: Install iftop To Display Bandwidth Usage Per interface By Host

I am running Red Hat Enterprise Linux on IBM based system. How do I display bandwidth usage on an interface by host in real time using command line option? How do I monitor bandwidth usage in a real time on RHEL or CentOS Linux based server? How can I install iftop utility on CentOS or RHEL server using the yum command?
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Ubuntu: Stat / Stop / Restart Iptables Firewall Service

I am a new Ubuntu Linux version 12.04 LTS user. How do I stop or start iptables based firewall service on Ubuntu Linux using bash command line options?
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OpenSSH Config File Examples

How do I create and setup an OpenSSH config file to create shortcuts for servers I frequently access under Linux or Unix desktop operating systems?
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SSH Into Google Cloud Compute Engine Instance Using Secure Shell Client

I need to set and test my web-app using Google cloud compute engine. How do I connect to an Instance Using ssh on Ubuntu Linux or Apple OS X based system?
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