Technology Insights

Verify a External USB Hard Drive On a CentOS Linux Computer

Recently I had a hard drive crash that was in a Windows XP laptop. The drive would  not mount under Windows however I was able to eventually mount it under Linux and rescue some of the data. In this article I will describe how to verify the USB hard drive enclosure is seen on a CentOS Linux computer and verify that Linux is able to see the USB device and the drive.

First you will want to remove the hard drive from your Windows XP computer and physically mount it into the USB hard drive enclosure. This will involve connecting it inside (IDE or SATA) and then plugging the USB cable or cables into the CentOS server. Since the hard drive is damaged its hard to know if its not reading it or if you have something misconfigured, a loose cable, etc. Below are a couple tips to make sure that the hard drive is being recognized via the USB connection.

Technology Insights

Install a Ruby Gem From Your Local Linux Server

Installing a gem locally is extremelly easy if you follow the steps below. I was recently in a situation where I had to upgrade a gem quickly to resolve a bug but the latest version of the gem located on http://gems.rubyforge.org was older than what was necessary. You need to locate the .gem file for the gem that needs to be installed and get a copy on the local server. In my case I happened to have a gem server that had ben installed but the web access was down at the moment so I SCP’d (secure copy) it to the local server and placed it in /usr/local/src.

Once you have the gem moved onto the local server issue the below command to install.