Technotes

File System Reserved Characters

Different operating system have support different characters. In general, the following characters should not be used for file or directory names;

Linux: Determine File Mime Type And/or Character Set

Simple command to determine a file's mime type and character set;

Ubuntu 11.04 Natty Narwahl Upgrade

Ubuntu 11.04, Natty Narwahl, was released last month and it's time to upgrade computers to the new OS. As always I approach OS upgrades with a bit of intrepidation. While most go just fine, some of the computers I use have had fits going from release to release. Before I upgrade the computers I use at work, I'll usually do my personal machine at home then my wife's machine. Followed by my work laptop, then my workstation. Here's how things have progressed;

Ubuntu: Dell OpenManage Installation

Anyone looking to install Dell OpenManage on a server running Ubuntu should start with the instuctions located at:

What Is Load Average?

Have you ever used top or uptime from CLI? Both display Load Average in 1, 5, 15 minute intervals. But what does it mean? The best analogy I've come across describes this as traffic crossing a one-way bridge. Odd, I know but bear with me...

First, the Load Average is the average number of CPU requests processed and waiting for execution in the displayed time period (1, 5 or 15 minutes). That's a rather vague description for a newbie. So, let's make it understandable;

Ubuntu Server With Minimal Gnome Desktop

Installing Ubuntu server leaves us with a CLI (Command Line Interface) only. Now there's nothing wrong with that. But, Linux sports all these tools on the GUI side that makes traditional server administration easier and more pleasant. Not-to-mention it helps training newbies a bit easier too. Besides, it's nice to have access to the GUI tools from time to time.

Ubuntu Lucid Upgrade: Dell T3500 Disaster

My system at work had been acting funky for months. Every now and again, the monitor would go non-linear and I'd get no response from the mouse or keyboard. It would normally still be accessible remotely. So, I'd just reboot it that way and move on. I was pretty sure it was a memory or video card issue.  But, I read where Ubuntu had some problems with the NVidia cards. I figured I'd wait 'til Ubuntu released 10.04 and do a fresh install.

SSH: Stop Asking To Add New Hosts

An annoying little thing. When connecting via SSH to another machine for the first time SSH always prompts;

---
The authenticity of host 'xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx)' can't be established.
RSA key fingerprint is ..............
Are you sure you want to continue connecting (yes/no)?
---

PHP CLI: Rsync Script

Here's a handy script to run rsync from the command-line that prompts for source and destination paths;

Ubuntu: Change Hostname

I had to snag this one for posterity from http://www.ducea.com/2006/08/07/how-to-change-the-hostname-of-a-linux-system/