When executing the apt-get update command, you may get “There is no public key available” warning message. This article explains how to solve this warning message message.

$ apt-get update
Get:1 http://debian.linux.org.tw lenny Release.gpg [394B]
Get:2 http://debian.linux.org.tw lenny Release [73.6kB]
Get:3 http://debian.linux.org.tw lenny/main Packages [5310kB]
Fetched 5384kB in 1m13s (73.5kB/s)
Reading package lists... Done
W: There is no public key available for the following key IDs:
4D270D06F42584E6
W: You may want to run apt-get update to correct these problems

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If your internet speed is really slow, you may want to identify your current upload and download speed in Mb/s before calling your ISP provider.  There are lot of websites out there you can use to calculate the speed. This article explains how to perform the internet bandwidth speed using speedtest.net. 
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Photo courtesy of sean dreilinger

This article is part of the on-going Software for Geeks series. SoX stands for Sound eXchange. SoX is a cross-platform command line audio utility tool that works on Linux, Windows and MacOS. It is very helpful in the following areas while dealing with audio and music files.

• Audio File Converter
• Editing audio files
• Changing audio attributes
• Adding audio effects
• Plus lot of advanced sound manipulation features

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Disk space is never enough. On an on-going basis system administrators will be getting request to increase the disk space on a server.

In this article, let us review how to add new physical disks and create a virtual disk with a RAID configuration on an DELL PowerEdge Server using PERC 6/i Integrated BIOS Configuration Utility.

The new DELL Servers has the ability to create RAID 0, 1, 5, 6 and 10 using the hardware controller.

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A while back we discussed about 12 powerful PuTTY add-ons. When you are working on production support or on a critical project that require 24×7 support, it is essential that you connect to the remote Linux server from anywhere. I found having a SSH client on my phone is very convenient for a quick status check and troubleshooting.

MidpSSH is a SSH and Telnet client for mobile device.

This is a step-by-step guide on how to connect to a Linux server from blackberry phone using MidpSSH software.

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Photo Courtesy: B Zedan

This article is part of the on-going Vi / Vim Tips and Tricks series. Vim is commonly mentioned as text editor, not text creator. Why ? Because we spend lot of time editing an existing text than creating new text.  In the text editing, text/pattern substitutions becomes a vital part.

In this article, let us review how to perform both basic and advanced text and pattern substitution features in Vi and Vim Editor. These features are explained using 12 very practical and powerful text substitution examples.
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Photo Courtesy: mattblaze

Best practice recommends that users keep changing the passwords at a regular interval. But typically developers and other users of Linux system won’t change the password unless they are forced to change their password.
 
It’s the system administrators responsibility to find a way to force developers to change their password. Forcing users to change their password with a gun on their head is not an option!. While most security conscious sysadmins may be even tempted to do that.
 
In this article let us review how you can use Linux chage command to perform several practical password aging activities including how-to force users to change their password.
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