08 Jul 09 Getting Your Ubuntu 8.10 Notification Back In 9.04
If you miss the notification that used to be in the 8.10 notification area telling you new updates are available you can get it back by quite easily by issuing the following command.
gconftool -s --type bool /apps/update-notifier/auto_launch false
Then you just kill and restart update-notifier and you will have your icon for update-notifier back (to check it straight away, run: sudo apt-get update).
Note: This will also stop the update manager window from automatically popping up every time you run apt-get update which is reason enough to do it on its own.
03 Jul 09 Cleaning Up Ubuntu
This is just a quick look at cleaning up an Ubuntu system. This is all documented elsewhere by an abundance of people, some of whom I no doubt took this off in the past and have forgotten where now (If you’re that person, then thanks very much, this stff has been coming in handy for me for a few years now).
Removing Residual Configs
The first step is to remove all of the residual configs lying about your system. These are configs which, as the name suggests, have been left behind by removed programs. To do so the we need to open Synaptic. You can find that in the System menu:
System > Administration > Synaptic Package Manager
Once we are in Synaptic we can click on the status button down the bottom left. This will separate your packages into sections based on their status. The one we are looking for will have the words “residual config” in the name. Select all these packages and right click on them. In the menu that appears choose “Mark For Complete Removal“. You can then click “Apply” at the top of the screen.
That’s it. You have now removed all your residual configs.
Removing Partial Packages
You will need to open a terminal for this one. To do so hold down “Alt+F2“. A box should appear, into which you can type “gnome-terminal” to open a new terminal. In the terminal you simply need to type the following to remove these partial packages:
sudo apt-get autoclean
Once you’ve put in your password etc that’s it. All gone.
Removing Unnecessary Locale Data
Theres a nice little app called localepurge that will get rid of all the locale data that you don’t need. This can amount to quite a substantial amount of space. The first step is to install localepurge. In your terminal type:
sudo apt-get install localepurge
After installing localepurge will require that you configure it with the locale’s you want to keep. It will present you with a list of abbreviations from which you can choose. Scroll down to the one that suits you best (i.e. for myself I kept en_IE.
That’s it. It will run automatically after each install and remove unnecessary locale data.
Removing Orphaned Packages
The app deborphan can grab all your orphaned packages and be used to remove them (be a bit careful with this one as sometimes it can remove something you need – it hasn’t happened to myself but I have heard of it happening). So to install the package, in your terminal type:
sudo apt-get install deborphan
To run the app you just need to type this at your terminal:
deborphan | xargs sudo apt-get -y remove --purge
This will remove all the orphaned packages on your system.
That’s it then, you should have free’d up a good bit of space on your system now and it should be a little tidyer than before!
19 May 09 GNS3 – Graphical Network Simulator
“GNS3 is a graphical network simulator that allows simulation of complex networks.”
I was recently pointed in the direction of this app as a pretty nice graphical interface to the Dynamips / Dynagen router simulation. It still uses Dynamips / Dynagen underneath, along with Pemu (a Cisco PIX firewall emulator based on Qemu), but allows you to do graphically what you normally have to do using textual config files.
The interface is really nice and you can drag and drop in routers, create links between them, and start and stop them through the GUI. Theres no real difference from what I can see in performance etc, so many people would just turn a blind eye and figure, “Why bother, the config files are handy enough”, but it does mean you don’t have to bother with the configuration for the most part, and can just concentrate on the actual task at hand.
And the best news is it’s packaged for Ubuntu! I’m sure this is the case for other distro’s too but I haven’t checked. So all you need to do is:
sudo apt-get install gns3
You can check the documentation etc out at: http://www.gns3.net/
19 Feb 09 Ubuntu Dynamips And Dynagen Starter Guide
This is a slimmed down version of a combination of the Dynamips / Dynagen Tutorial and a few other Ubuntu specific sources. In fact, you could call it a quick and dirty guide to get you up and running. I reccommend using the Dynamips / Dynagen Tutorial once you have finished here picking up at the Running Sample Lab #1 section. I couldn’t write this better than it is there.
Installation
Dynamips and Dynagen are both in the Ubuntu repository so installation is as simple as an apt-get install. To this end run the following:
sudo apt-get install dynamips dynagen
Congratulations. That’s it for installation.
IOS Image
You’ll need to get yourself a Cisco IOS image for use with the emulator. Once you have one it’s generally a good idea to uncompress the image before using it as it will speed up the boot process. Use this command to do so:
unzip -p c7200-jk9s-mz.124-13b.bin > c7200-jk9s-mz.124-13b.image
Note that this will throw an error but you can safely ignore it.
Configuring Your Telnet Client
Your telnet client should be correctly configured upon install. You can find the config file for this in /etc/dynagen.ini if your curious. You’ll find a line like the below uncommented which is your telnet configuration.
telnet = xterm -T %d -e telnet %h %p > /dev/null 2>&1 &
Configuration File
You will need a configuration file for your router(s). You can find an example one (we’ll use this example config for the rest of this guide) in /usr/share/doc/dynagen/examples/sample_labs/simple1/. We’ll use the sample1.net file from here for this guide so copy this file to wherever you have your “working directory”.
The .net file will look like this:
[localhost]
[[7200]]
image = /opt/7200-images/c7200-jk9o3s-mz.124-7a.image
npe = npe-400
ram = 160
[[ROUTER R1]]
s1/0 = R2 s1/0
[[router R2]]
# No need to specify an adapter here, it is taken care of
# by the interface specification under Router R1
So, according to the config we are running this router instance on localhost, and defines all the defaults that will be applied to any 7200 router instance we create. This makes things easy, by allowing us to specify common things like RAM size and IOS image only once.
Each of our router instances is going use an NPE-400, and be allocated 160 MB of RAM .
We are defining a virtual router instance with the ROUTER keyword. The string following this keyword is the name we are assigning to this router, in this case “R1”. This name is just the name that is used by Dynamips / Dynagen. It has nothing to do with the hostname that you assign in IOS to the router.
The s1/0 = R2 s1/0 line states that we are going to take R1’s Serial 1/0 interface, and connect it to R2’s Serial 1/0 interface (via virtual back-to-back serial cable). Dynagen automatically “installs” a PA-8T adapter in Port 1 to accommodate this connection on both R1 and R2.
We also create a 2nd router named R2. This is the same R2 that is referenced in the line above that connects R1 and R2’s serial interfaces. As the comment says we don’t need to specify an adapter here as it is taken care of by the interface specification under Router R1.
The only change we need to make to the .net file above is to change the value of “image=” to the path of your IOS image. For instance:
image = /home/$USER/ios/7200/c7200-jk9s-mz.124-13b.image
That’s all the configuration we’ll need for the moment.
Starting The Server And Management Console
Before you start the server cd into your working directory where you plan to store the information about your router(s). There are a lot of files created when starting both the server (dynamips) and console (dynagen) so best to be aware of this as they will be created in your working directory wherever you are.
To run the server (-H 7200 means on port 7200) in the background use:
dynamips –H 7200 &
You can now start your console with the command:
dynagen sample.net
Using The Console
At this point you are best of continuing from the Running Simple Lab #1 section of the Dynamips / Dynagen Tutorial. Good luck!
12 Feb 09 Accessing Gnome Trash Folder From Terminal
I’ve often found that I can’t delete items I’ve copied from a CD or DVD using the GUI Trash folder. In fact, this can happen with a variety of files from a variety of places but, to be honest, I have a habit of not correcting the permissions on these files before blindly hitting delete. Sometimes you just forget these things.
In any case this can be extremely infuriating, and inevitably results in looking around your /home directory running something like…
find /home/$USER/ -name ‘Trash’
…which will find what your looking for pretty quickly. But in case you’re feeling especially lazy here’s the directories you’re looking for. You’re going to need remove files from the two directories listed, just to keep it all clean.
/home/$USER/.local/share/Trash/files
/home/$USER/.local/share/Trash/info
