Firefox 3.5 on Ubuntu

To install or upgrade to Firefox 3.5:

sudo sh -c "echo 'deb http://ppa.launchpad.net/ubuntu-mozilla-daily/ppa/ubuntu jaunty main' >> /etc/apt/sources.list"
sudo sh -c "echo 'deb-src http://ppa.launchpad.net/ubuntu-mozilla-daily/ppa/ubuntu jaunty main' >> /etc/apt/sources.list"
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 247510BE
sudo apt-get update && sudo apt-get install firefox-3.5

Sending Tweet's From the Command Line

Saw tweeted by commandlinefu.com that you can use Curl to send tweets! I've been doing this an aweful lot lately. When I'm working, and need to send a quick tweet, I just use my handy little sendtweet.sh script.

Here is my "sendtweet.sh" script:
------------------------------------------------------

#!/bin/bash
if [ ! $1 ]
then
echo "Send Tweet. Usage:"
echo "$0 message"
echo
echo "This $0 script sends twitter status updates"
echo
echo "Make sure you escape anything but alphanumerics"
echo
exit
fi

curl -u twitter_username:twitter_password -d status="$*" http://twitter.com/statuses/update.xml
------------------------------------------------------

The if look is just to prevent me from doing anything stupid. You have to escape anything but alphanumerics, so usage is like:

sendtweet.sh Cool\, I\'m sending tweets from bash\!\!\!

Thought you all would enjoy that ;)

Syndaemon Touchpads

For those of you who have laptops and have that annoying problem of accidentially hitting the touchpad while working, I stumbled across this little blog post while surfing the #ubuntu hashtag on Twitter:

http://david.wonderly.com/archives/29

basically its about syndaemon, which can monitor for keyboard activity, and disable the touchpad while until your done typing.

Good bye annoying accidential touches!

Chromium on Ubuntu

Chromium has gotten pretty useful now. Here's how I installed it from the Ubuntu PPA:

================================
vim /etc/apt/sources.list
----- add -----
deb http://ppa.launchpad.net/chromium-daily/ppa/ubuntu jaunty main
deb-src http://ppa.launchpad.net/chromium-daily/ppa/ubuntu jaunty main
----- add -----
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4E5E17B5
sudo apt-get update
sudo apt-get install chromium-browser
================================

Start with:

chromium-browser --enable-plugins

to get Flash support, which is a little buggy. Otherwise, its a pretty nice browser, and a decent option for Lean installs

Force upgrade of PEAR

Recently I received this error while trying to install a package in PEAR:

# pear install HTTP_Request
HTTP error, got response: HTTP/1.1 410 Gone
Didn't receive 200 OK from remote server. (HTTP/1.1 410 Gone)

The solution, was to upgrade PEAR:

pear upgrade --force http://pear.php.net/get/Archive_Tar http://pear.php.net/get/XML_Parser http://pear.php.net/get/Console_Getopt-1.2.2
pear upgrade --force http://pear.php.net/get/PEAR-1.4.3.tar
( OR: pear upgrade --force http://pear.php.net/get/PEAR-1.3.3 _IF_ your existing older than 1.3.3)

Tweetdeck on non-GNOME/non-KDE systems

I had some considerable difficulty getting tweetdeck running on Ubuntu Xfce. For some odd reason tweetdeck starts, but nothing works. Something to do with session management.

Here's the solution I found digging around the internet. Put the following in a script, call it say /usr/bin/tweetdeck.sh:

----------------------------------------------------------------
#!/bin/bash

GNOME_DESKTOP_SESSION_ID="whatever" /opt/TweetDeck/bin/TweetDeck
----------------------------------------------------------------

Make the script executable, and change your launchers to run that script instead.

Now TweetDeck runs perfectly on Xfce, and I assume any other odd window manager/desktop environment.

Fedora Core 6 EOL and Ensim

Fedora recently set the dreaded EOL on Fedora Core 6. For most this is not a problem, but for servers running Ensim / Parallels Pro, this can lead to servers which are unable to be updated. To get around the default YUM repos that are not broken, I ran the following command:

python ensim-installer.py --ftp-server=download.pro.parallels.com --extra-source=http://download.pro.parallels.com/ensim/repos/fedora/4/i386/extras/ --os-source=http://archive.fedoraproject.org/pub/archive/fedora/linux/core/6/i386/os/ --updates-source=http://archive.fedoraproject.org/pub/archive/fedora/linux/core/updates/6/i386/

This will update Ensim using the archived Fedora releases.

Swappiness on Linux

Swappiness is a Linux kernel setting that controls how often your swap is used. For the most part there is no need to tweak this setting, the default values are fine. However under some circumstances, especially on laptops or low memory systems, you may want to adjust it.

The value could be set from anywhere from 0, no swappiness, to 100, swap as much out as you can. Different distributions set this differently. On Ubuntu and CentOS, the default is 60. At a bare minimum you should set it to 10, since a setting of 0 could lead to a system lockup if you run out of RAM.

For example, I'm currently using two laptops. One of my laptops is a Compaq Presario 700. It has a 500 mgz Athlon processor, and its motherboard supports a maximum of 384 megs of PC100 RAM. Older machine, and it still runs perfectly after about 8 years of use. It has a bare minimum installation of Ubuntu with the XFCE4 desktop environment. I want to use Firefox, which on a machine like this can take over the system pretty quick. I put the following in /etc/rc.local:

echo 100 > /proc/sys/vm/swappiness

That will cause everything in the background to get out of Firefox's way when it needs the RAM. When switching applications the desktop doesn't snap very well, since it has to retrieve code from swap a lot more, but it does give Firefox and other memory intensive applications the resources it needs to preform well. In fact, for the most part the machine seems to run all around better with swappiness turned all the way up. Of course, this will kill the battery life, but the battery failed years ago, so it really doesn't matter.

On the flip side, my second laptop is a Acer Aspire Gemstone with 1.7 Ghz processor with 2 gigs of RAM. I have a similar installation of bare minimum Ubuntu plus XFCE4. Again, I use Firefox and some office apps, however since I'm using such a lightweight desktop I'm hard pressed to ever make it past 1 gig of RAM. In fact, the last time I swapped out was when I was using VirtualBox and Firefox leaked memory due to a bug on a Flash based web page, but that was a long time ago. That was also before upgrading from 1 to 2 gigs of RAM. Since I have more than enough memory than I'll ever use, I set the following in /etc/rc.local:

echo 0 > /proc/sys/vm/swappiness

This is a dangerous setting, so I make sure I have a memory monitoring app on my panel. If I ever run out of RAM, which I doubt under the current setup, the machine will lock, and lock hard. The benefits however are tremendous. There should be never a reason to swap out, and when running on battery an errant spin up due to unnecessary swapping in and out could possibly lead to a loss of five to ten minutes of battery life. Any road warrior will tell you that 10 minutes on battery might as well be an hour.

You can adjust this setting on the fly as well. All you have to do is echo your value to the swappiness file just like in the rc.local examples above. For desktop machines with a gig of ram or more, most likely you won't see much of a difference no matter what you set it too, but it could be a handy tool for laptops with limited, or plenty, of resources.

Just another admin blog

I'm Arthur H. Johnson II, aka bytor4232, and I'm a sysadmin. My specialty is in server administration using Linux, however I've been known to take a crack or two at Windows and UNIX. Currently I work for AbleTeam and Hard Drive Hotel as their primary technical lead, and admin around 150 servers for our customers. I also provide technical support for Super Cheap Web Dev, my wife's company, on a moonlight basis.

The primary purpose of this blog is to give back to the internet community as a whole by sharing some nuggets of knowledge aloung the way. All of what I know was learned for free thanks to Open Source Software and the GNU/Linux Operating System. My current Linux obsession of choice is Ubuntu and its various flavors. My current adventures in Ubuntu is going to be documented in my Lean Ubuntu blog. In my spare time I also lend technical support on the various Ubuntu Community Support channels where I'm mostly known as bytor4232. You can follow me via Twitter, where I'm known as arthurjohnson.