The Weatherman

Professor Randy Pausch of Carnegie Mellon University gave his last public lecture entitled “Really Achieving Your Childhood Dreams” (click title to see Google video of it).

Although Professor Pausch has been diagnosed with terminal pancreatic cancer (see his blog), he gives an excellent lecture on living your life to its fullest and achieving your dreams. Be sure to take the time and watch it - it’s definitely worth it. It’s amazingly upbeat and inspirational.

Pay attention to the “head fakes”.

I wonder if he saw the biggest head fake of them all…One of his themes is enabling the dreams of others. He spends his career striving to make it easier for anyone to become a programmer. He first enables the dreams of 1 student, then 50 students, and now with Alice he will touch potentially millions. But, he will never instruct or touch more than he will with this lecture. This lecture is something everyone can take something from…not just wannabe/potential programmers. Anyway, maybe I’m looking too much into this irony (or ‘head fake’) but it is definitely there.

I found some cool websites discussed over on TechCrunch.  The first is a new travel site that is still in private beta called Yapta.

Another travel site?  What is so special about that?  You perform fare searches using the site and then bookmark fares that you find.  It will track the fare and keep you informed of fare changes.

If you purchase a ticket through the site, it will continue to track the fare for you.  If the fare drops, you can get a refund.  I guess this is always the guess, however we never know when the fare drops so most people don’t know to request the refund.  From TechCrunch, the  beta users have reported the following returns:

In beta testing with 275 users over the last several months, Yapta found that 34% of purchased tickets became eligible for a refund. The average refund was 16% of the ticket price, or $85. During the beta period that worked out to a total of $28,900 in aggregate potential refunds, or about $100 per beta user.

That’s not too shabby.  Once it goes public, this site is definitely one to check out.

The other site is Newsvine.  It’s a news portal combined with a blog portal.  You can setup your own Newsvine site (see mine at pabloa3.newsvine.com) where you can publish your own articles or seed Newsvine with articles you have read.

Also, both of these are local Seattle products.

Yep, Steph gave in and let me pickup an Apple MacBook.  I got the black one with 120 GB HD and 1 GB RAM.  It’s a pretty sweet box.  Now I’m working on copying my music from my old laptop over to the new laptop.

I also picked up the EyeTV Hybrid.  With a little antenna I had lying around I was able to pick up about 5 channels from our downstairs - not too shabby.  Now I can watch HD on the laptop.

Joe Brockmeier has two articles on Linux.com called the Sysadmin Toolbox.

My sysadmin toolbox and My sysadmin toolbox: second helping

He lists out many good tools that sysadmins should be aware of and be familiar with. My top 10 is basically similar to his with a few changes.

vim
This is where it all begins…with a good editor that you can use on every unix box. I haven’t spent nearly enough time experimenting with vi. Unfortunately I tend to learn things until they become usable but do not take the time to become an advanced user. Nevertheless, I’m able to get things done quickly with vi and I couldn’t imagine editing a file with anything else.

curl
While I like wget, I’m a bigger fan of curl. I enjoy it’s trace option and the libcurl support for multiple languages.

screen
I’m pretty new to screen (been using it for about a year) but I find it invaluable. By far the best feature is the ability to detach/attach remote sessions. It makes it easy to take work home or vice versa. In addition, the key bindings are nice. It does take a little ramp up time to get the ideal setup.

cygwin
Isn’t cygwin for windows? Yes, I know, it’s for windows. But, as much as I can’t stand windows, I still use it at work for stuff like Yahoo Messenger, Word/Excel, or Visio. Cygwin allows me to setup an XDM session with my FreeBSD box and from there I can easily copy/paste between unix and windows. I basically leave the XDM session maximized and just pull up the few windows pieces (eg, Word) that I need.

perl
I learned Perl and decided I didn’t need Awk and Sed. With Perl I can write a program to do anything or run some quick commands right at the command line.

bash
Just an all round solid shell environment.

ssh
Nothing unusual here. But I think ssh needs to be mentioned since every sysadmin uses (or should be using) it. Plus you can run commands remotely with it.

tcpdump/ethereal
Great tool for analyzing network traffic, but I would never user tcpdump without ethereal. The benefits of ethereal are too great (like following a tcp stream) to not warrant its use.

gdb
It’s nice to get backtraces from cores or stuck processes.

lsof
I don’t use this much, but when I need it, it’s invaluable at helping me find large open files that appear deleted.

That would be my top ten list…at least that’s what I thought of tonight.

It’s not often that my wife introduces me to something very new and cool on the Internet. Tonight she emailed me about a relatively new music service called Pandora. So what is it…well from the FAQ,

Pandora is a music discovery service designed to help you find and enjoy music that you’ll love. It’s powered by the Music Genome Project, the most comprehensive analysis of music ever undertaken. Just tell us one of your favorite songs or artists and we’ll launch a streaming station to explore that part of the music universe.

They have analyzed 300,000 songs from 10,000 artists for a multitude of characteristics (up to 400). This information allows Pandora to create a radio station based solely on the user entering a song or artist. From there, the software will play songs that meet similar characteristics. The user can give the suggestions a thumbs up or thumbs down. So how is this different from other radio station like services? This one works. The due diligence Pandora has performed in song analysis shows.

In addition, they provide a very simple, sharp flash player that works on common browsers that have flash support. Right now I’m listening from my Gentoo Linux desktop box on Firefox. I couldn’t do that with Yahoo Music Engine or ITunes.

In addition, Pandora has provided links to ITunes to purchase individual songs or Amazon.com to purchase albums.

So how much does this service cost? They provide a free version that is entirely supported by advertising or you can pay $36 for the year. This is one of those services I believe people will easily pay for even though it’s free.

Kudos to an excellent product.

I came across this GPL’d set of mapping tools called GMT or The Generic Mapping Tools. It’s amazing how quickly one can create a map with relatively decent detail. This is all I did to get up and running:

1. Download and install netCDF
2. Downloaded the install script
3. Ran install_gmt

They provide an online form for creating the parameters used by install_gmt - however I had problems getting it to work. So I just ran install_gmt in interactive mode and answered the questions on the command line. Finally I started using their tutorial and within minutes I ran the following command:

pscoast -R236.5/238.5/37/38.5 -JM6i -P -Df -Ia -V -B5g5 -G180/120/60 -Na -W > map.ps

and I used ImageMagick’s convert to create a png file that you see here:

Very impressive tool. You can add political borders, including state borders with one command line parameter.

So why would one want this? Well, organizations like the NWS provide tons of data but much of it is longitude and latitude. GMT allows you to create maps that you can later plot against with mapping data.

OK, so not the most interesting use, but it’s a start.

Today I had to setup iptables for doing some very basic ip filtering on two servers. There is quite a bit of information scattered around the internet, but it took a while to get some helpful pieces. I suggest starting with netfilter.org for a good selection of documentation, check out Mastering IPTables article, and this tutorial is a good beginner starting point.

iptables -F INPUT

use this to flush the INPUT chain. This is good to add to the beginning of any script you write. Otherwise, your old rules remain unless your script specifically replaces them. The INPUT chain deals with packets destined for the local machine. There are two other chains: OUTPUT and FORWARD. OUTPUT applies to packets originating locally, and FORWARD applies to packets coming into the server but not meant for the server. You can also make your own chains. See the linked articles for more information.

iptables -A INPUT -s [ip address, network] -p tcp –destination-port ssh -j ACCEPT

this sets up the server to accept ssh connections from a specific set of IP addresses or from a specific network. You can eliminate the -s paramater to allow ssh from any server. You can substitute the ssh for any port number or service that you need a rule for.

In addition, you can change the ACCEPT to DROP or REJECT. DROP will just drop the packets with no response. REJECT will actually provide the ‘connection refused’ error. For example, I may list some rules for accepting tcp traffic on port 9999 from certain IPs, then I can follow up with the following to reject the any other traffic.

iptables -A INPUT -p tcp –destination-port 9999 -j REJECT

If you want to check your progress then type

iptables –list

I also placed these statements into a shell script (/etc/firewall.sh) which I called from within /etc/rc.local. However, there are plenty of samples of more sophisticated startup scripts handling these rules. Be sure to check out other resources like Chapter 9, Linux Network Administrator Guide

Once again, I’m not a network or security expert…I just needed to block access to a few ports outside of a couple of servers. iptables proved to be a good, simple solution.

Yes…I have ordered one. I ordered the 60GB black version. I’ve been waiting a long time for the ipod to play video. I wish it had recording capabilities, but the build quality, features, and media available more than make up for this.

I’ll keep you posted with my thoughts on the ipod once it arrives. I should receive it late next week.

This has been a pretty hot topic at works for months. This 64 bit computing article provides a basic understanding of 64 bit. In additon, read the comments below the article for some opposing views. This is a pretty high level view of 64 bit computing…for something more advanced I would check out the articles on the cpu/chipsets page at anandtech.com

Ok, so I got MythTV 0.16 working on my old Sony Vaio desktop. I’m pretty impressed with the OS overall. It has a very generous package database and Portage is an amazing tool. So I decided to rebuild my newer desktop machine (Shuttle SN85G, AMD 3200, 1GB RAM, 160GB SATA). I had originally built this with Fedora Core 2 32 bit.

Now I’m a pretty impatient person. That holds true when installing OSes. So I need to built up a little patience before installing Gentoo…it takes days. I also attempted to install 64bit Gentoo…without going into details, I didn’t complete that installation.

I reverted to the 32bit version instead. The installation was relatively easy once again. When booting I specified ‘gentoo noapic’ or else my SATA drive wasn’t available. The LiveCD recognized my hardware so I made sure to note the drivers — this is helpful when configuring the kernel later. My boot partition is ext2 and my main partition is reiserfs.

As for kernel configuration, I had to enable forcedeth for enabling the ethernet interface on the nforce3 motherboard. Otherwise it was fairly standard. I think I only rebuilt the kernel about 5 times to get what I wanted.

I have the following applications running on it

• Firefox 1.0
• Thunderbird 1.0
• Sendmail, Procmail, Dovecot, Fetchmail, Spambouncer for email management
• mplayer
• gaim
• mysql
• my weather app

I plan on installing gimp, open office, and various development tools as the days go on.

It a good OS…just need patience since everything is built from source.

PC Magazine has an article on the Top 15 Firefox Extensions. I actually found this on Galaxy

• About site 0.1.1
• Adblock 0.5.2
• Bandwidth Tester 0.4.1
• Cards 0.16.1
• Clusty Toolbar 1.0.2
• ColorZilla 0.8.2
• DictionarySearch 0.7
• ForecastFox 0.5.8
• FoxyTunes 1.1
• GoogleBar 0.9.0.30
• Google Preview 0.8
• MapIt! 0.4
• ScrapBook 0.12.0
• Tabbrowser Preferences 1.1.1
• xMirror 0.1.1

So far so good. I now have my older Sony Desktop running Gentoo 2004.3 I basically followed the Gentoo Installation Handbook. I also threw in a second 80GB hard drive. The primary drive is a 40GB drive for the OS

The 80GB drive is for storing my MythTV recordings.

I was able to install ivtv for my Hauppauge PVR 350. I actually emerged the ivtv driver from Gentoo. Of course, I had to recompile the kernel several times but ultimately I got everything to work. There are some helpful sites for the install, here is one. My kernel compile required similar changes to the aforementioned documentation…fyi, for me, I was only able to get the intel8×0 sound card working as a kernel module.

I was able to emerge MythTV without much difficulty. It just took a while for the compiles to complete. I had some minor differences compared to the online directions but they were easy to figure out.

That’s it

A few months back I put together a new system (Shuttle SN85 G4, 1GB Ram, 160GB SATA drive, DVD burner) and made this my main linux desktop (Fedora Core 2 32 bit). I had some issues installing 64bit Fedora Core 2…although I plan on trying 64 bit Fedora Core 3.

Anyway, my older PC (Sony P4 1.5Ghz, 384MB RAM) has been sitting idle. And it has a Hauppauge WinTV PVR 350. I had this setup and working before my hard drive failed - the second drive failed.

So, the Sony still has a 40GB drive (I plan on picking up an 80GB drive soon), and I thought it be fund to install Gentoo 2004.3. I’ve been meaning to give Gentoo a try for years but never had the free machine. It’s currently performing Stage 1…so I have a little time to kill.

So far the install has been very easy. The instructions have been awesome. Anyway, I hope to have a working gentoo installation within a few days. Stay tuned.