From the category archives:

Linux

Three Sysadmin Rules You Can’t (And Shouldn’t) Break

by Ramesh Natarajan on July 27, 2010

When I drafted this article, I really came-up with 7 sysadmin habits. But, out of those 7 habits, three really stood out for me.

While habits are good, sometimes rules might even be better, especially in the sysadmin world, when handling a production environment.

Rule #1: Backup Everything ( and validate the backup regularly )

Experienced sysadmin knows that production system will crash someday, no matter how proactive we are. The best way to be prepared for that situation is to have a valid backup.
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Bash String Manipulation Examples – Length, Substring, Find and Replace

by Sasikala on July 23, 2010

In bash shell, when you use a dollar sign followed by a variable name, shell expands the variable with its value. This feature of shell is called parameter expansion.

But parameter expansion has numerous other forms which allow you to expand a parameter and modify the value or substitute other values in the expansion process. In this article, let us review how to use the parameter expansion concept for string manipulation operations.

This article is part of the on-going bash tutorial series. Refer to our earlier article on bash { } expansion.
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How to Fix wget Connection Refused Error when I’m behind a Proxy

by SathiyaMoorthy on July 23, 2010

Question: While downloading using wget, I get the following error “Connecting to <URL>.. failed: Connection refused.”. I’m behind a proxy server. How do I fix it?

Answer: Export the http_proxy variable with your proxy server name or ip address and then try downloading as explained below.
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HowTo: 10 Steps to Configure tftpboot Server in UNIX / Linux (For installing Linux from Network using PXE)

by Balakrishnan Mariyappan on July 22, 2010

In this article, let us discuss about how to setup tftpboot, including installation of necessary packages, and tftpboot configurations.

TFTP boot service is primarily used to perform OS installation on a remote machine for which you don’t have the physical access. In order to perform the OS installation successfully, there should be a way to reboot the remote server — either using wakeonlan or someone manually rebooting it or some other ways.

In those scenarios, you can setup the tftpboot services accordingly and the OS installation can be done remotely (you need to have the autoyast configuration file to automate the OS installation steps).
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