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 )

I recently learned that “wget” can continue getting a partially-downloaded (resume download) file. I am unable to find wget command on Mac OS X. How do I install install wget on Mac OS X (Mountain Lion/ Mavericks / Snow Leopard)? How can I install wget in Mac OS X without 3rd-party repo such as Homebrew or MacPorts?

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My MySQL database installation has been corrupted. I would like to delete old mysql server. How do I reinstall MySQL database server version 5.x on Linux or Unix-like oses? A software upgrade broke my system. How can I uninstall and re-install mysql again to get fresh full mysql again?

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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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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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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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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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I need to tunnel X Window securely over SSH bases session so that I run X program on my remote Linux/Unix server/workstation and get back display to my Apple Macbook pro laptop. I tried the ssh -X user@server1ssh -Y user@server2 command on both OS X Mountain Lion and Apple OS X Mavericks. But, I am unable to use the ssh command with X11

How do I fix this problem on OS X and enable X11 forwarding with ssh command? How do I install XQuartz (X11.app) server on Apple OS X Mountain Lion or Mavericks?

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