How to change the DNS servers in Ubuntu

You might want to change the DNS server if your ISP’s servers can sometimes be slow or outdated.

sudo gedit /etc/resolv.conf

and change or add the lines:

nameserver your_DNS1
nameserver your_DNS2

You can add as many lines like these, but two should be enough.
Test the used domain name servers careful!

#dns-nameserver 192.168.0.1
#dns-nameservers 192.168.0.1 192.168.0.2
#dns-search somedomain.org
#dns-domain 192.168.0.1

Edit: Serge’s comment (the first one) made me search a little bit.
After searching google it wasn’t totally clear if the DNS should be configured in resolv.cof or /etc/network/interfaces, so I took the GUI for a spin.
I’ve set up the DNS trough the GUI and checked the changes inside both locations.
The DNS servers I addes, became listed inside the /etc/resolv.conf file.
So after all, I was right.
But as the configuration file starts with the line #Generated by NetworkManager, I was wondering if these settings would get overwritten by the NetworkManager.
So I wiped all configured interfaces from my computer and let the NetworkManager try its evil.
It worked like a charm and just added the line ‘domain morraye.local’ to the file, without erasing my dns settings.
This was tested on Ubuntu 9.04 and Ubuntu 9.10.

You might also want to play with these settings in your resolv.conf file

# dns-domain 208.67.222.222
# dns-nameserver 208.67.222.222
# dns-nameservers 208.67.222.222 208.67.220.220
# dns-search wikipedia.org

Note: When you’re behind a router, you should change the dns server at your router (unless it uses pass-trough DNS lookups)

One keyboard and mouse for multiple computers running Ubuntu

When you have multiple computers on your desk, it can be very annoying to switch keyboard an mouse each time you want to do something on one of the other computers.
So, you can solve this by just using one keyboard and one mouse for multiple computers without buying a hardware switch.
Synergy is a package, available from the repository that lets you share the mouse and keyboard over a range of different computers.
When synergy is active, your keystrokes will be send to the machine where your cursor is currently positioned.
The cursor will slide from screen to screen just as if you are working on one single system with multiple screens attached.
As far as I know, it’s not possible to drag windows from one machine to another. Which would be nice.
So if you’re a programmer and you’re still searching for a useful project, then this is just your bit.

Here is how you can easily start sharing your keyboard and mouse between different computers and screens using synergy on Ubuntu:

First off, install the synergy package and the QuickSynergy packages on each machine you want to use your pointer on with the command:

sudo apt-get install quicksynergy

Note that apt will install the synergy package as it’s required to run QuickSynergy. (QuickSynergy is in fact just a gui for Synergy)
When it’s installed, you’ll find QuickSynergy under the category ‘accessories’ in the application menu.

On the server:

The server is the computer where the used keyboard and mouse are attached to.
In the Share tab fill in the names of the computers where you want your keyboard and mouse to be operational.
Do not fill in the IP address, it won’t work.

Synergy server

To find out the name of your computer(s), open a terminal and type:

hostname

If all the hostnames are put in the right place, start the service by clicking ‘Execute’
Note that the window becomes gray.
You can now just minimize it and let it do it’s work.

On the client:

On the Client, fire up the QuickSynergy app and go to the Use tab.
Fill in the hostname of the server.
Note that you can also enter its IP, but know that when you’re using dynamic IP adresses, you’ll have to reconfigure this each time you fire up Synergy.

Synergy Client

Then just hit execute and minimize the window.
Now you can remove your keyboard and mouse from this computer.

When moving the mouse outside the window to the side you’ve configured the other computers position on the server, you’ll see your pointer go ‘troug’ the space between the two computers and appear on the other screen.
Als handy to know is that the clipboard is shared.
So you can actually copy something on machine 1 and paste it on machine 2. (text that is, don’t try this with data)

Note:
Synergy uses an unencrypted TCP/IP stream on port 24800. So if you’re on a network you can’t entirely trust, don’t use it unless you encrypt it.
I would even recommend ALL users using a wifi-network to encrypt the connection.
To Encrypt the Synergy data, you can simply follow the guide on their website.

Ubuntu-be on the Dipro Mega Market Ghent

Ubuntu-be will, as usual, be present at the next Dipro Mega Market event in Ghent.
Just like previous years, we’ll not only hand out free Ubuntu cd’s, but we’re also going to give advice and demo’s on how to use the most common applications.
Are you thinking about trying Ubuntu, but you don’t know how to start? Just come visit us.
We’ll give you the tips and help to get started.

But you could also just come by to say hi too of course. 🙂

If you feel like helping us out a bit, visit our wiki page here to find out what we still need or how you could help.

Ubuntu Server on VirtualBox returns error This kernel requires the following features not present on the cpu: 0:6

I installed Ubuntu Server 8.04 inside a VirtualBox (v 2.4.1_OSE) virtual machine.
The installation went smooth, but when I wanted to boot into my Ubuntu Server, it returned the following error right after GRUB:

This kernel requires the following features not present on the cpu: 0:6
Unable to boot – please use a kernel appropriate for your CPU

Screenshot or it didn’t happen?

Ubuntu Server on VirtualBox returns error

How to solve:

This can be easily resolved by enabling the PAE/NX option in the virtual machine’s settings.
This will expose the PAE of your CPU to the virtual machine.

Just:

  1. go to the homescreen of Virtualbox
  2. select your virtual machine
  3. click the ‘settings’ button on top of the screen
  4. click the tab ‘Advanced’
  5. check the box next to ‘PAE/NX’

Like in this screenshot:

Screenshot-testserver - Settings-1

Now, you can fire up your virtual machine again, and it will start up without this error.

Ubuntu-be update

Due to inactivity the last month on the Ubuntu-be mailing list, I had some catching up to do on the huge list of unread mails.
Amongst them I found this mail from  Pierre Buyle:

Hi,

for those requesting a Forum for Ubuntu-be, there is an alternative
solution (which has already been discussed in the past). Gmane
provides two web interfaces for our mailing list. A blog-like one at
http://blog.gmane.org/gmane.linux.ubuntu.region.belgium and a threaded
one at http://news.gmane.org/gmane.linux.ubuntu.region.belgium.

In addition, I registered the mailing list for archiving on Nabble
which also provides an forum like web interface at
http://n2.nabble.com/Ubuntu-be-f3354669.html

These three interface allow one to follow activities on the mailing
list without dealing with it as a bunch of mail. Both Gmane and Nabble
allow posting to the list through the Web interface (only for
subscribed user registered there).

So, if you’re interested in following the Ubuntu-be mailing list, you can easily do so without the ‘hassle’ of subscribing to it.
It’s also a perfect way to check it out for a while, as you don’t receive all these mails in your mailbox.

I have to say, it’s the first time I’ve seen the integrated nabble forum in action, and have to agree that it’s awesome.
Also the blog-styled layout of gmane is making the mailing list (more) enjoyable to read.

Of course, you can also just send a mail to the ubuntu-be mailing list.
Warning: This is a public medium! If you want to send messages to this list you’ll have to register first through https://lists.ubuntu.com/mailman/listinfo/ubuntu-be. Keep into consideration that every message posted will be visible in the public archives!

Tips: GRUB

GrubGRUB is one of the most common used bootloader on linux.
So, when using linux, and you’re a bit interesting in ‘what’s under the hood’,  it’s the first thing you want to learn about.

When you turn on your computer, the bios will start the bootstrap procedure from the primary boot-device.
(If you’re planning to run a LiveCD, you might make that your CD/DVD-rom drive) 😉
A bootstrap is in fact nothing else than having a small program, so that this can load a bigger one.
That’s the thing GRUB does, in short!
What you should remember, is that it’s important, and you would not like to break it.
If you do, you’ll render your hardisk unbootable.

So the first thing you want to do, is back up your MBR!
Why not just GRUB?
The MBR is a 512-byte segment, the first sector, on your harddisk.
GRUB takes 446 bytes, the partition table takes 66 bytes
and the 2 remaining bytes are for a signature.
You might want to keep these 3 intact.

Continue reading Tips: GRUB

The problem of starting linux

engine_startI was recently reading a discussion on the release of Windows 7.
The article went into detail when it came to the different versions that will be sold. There will be 7.
In the comment-section, I noted quite a lot of people arguing that this is too much to choose from for home users.
Well then, let’s take those people’s vision and apply it to the world of Linux.

Let’s go on a journey with someone eager to start using Linux (without a live cd).

Let’s say this is one of the wonderfull people informing themselves before they actually start doing something.
Then this user would trigger a search query on his favorite search engine for the value Linux.
Linux.org is probably the first link that will be hit, as the first result has a 42% chance of getting selected.

On Linux.org he/she’ll be learning a little on the principles of linux and the GNU licence.
After a bit of reading, she’ll know how wonderful linux is and appreciate the idea of openness.

As our imaginary person has a simple old spare computer that can be used to testdrive linux, he/she is convinced and ready to download her own copy.
But there is the first problem: Which linux distribution?

Continue reading The problem of starting linux

No more struggling with repository’s

reposearchAs everyone already knows, you should take a backup before changing something in Ubunut/linux.
But as we all forget sometimes, we’re off on a quest to find the standard file.
For example, the /etc/apt/sources.list file is one the most wanted files on the internet.
People tend to add repository’s, change the servers, clean out the unwanted stuff and most of all: break it!
I still remember the horror I brought to myself in the old days…
Now I can always fall back to my .back files 😉

Apparently I wasn’t the only one that noted the load of requests on the forums.
On the simplylinux.ch blog, the admin published a very neat source.list generator for Ubuntu.
It let’s you select not only your county, branch, and other basic repository items, but also includes third-pary repo’s such as Skype and Virtualbox.

I’m sure this tool will prevent a lot of people losing way too much time on searching for the right repository’s.

Jaunty Release-Party Ghent 09/05

I’m glad to announce:

On the 9th of may, there will be a Jaunty release party in Ghent! (free entrance)

First Promo Poster

The goal(s):

  • to provide general information on Ubuntu, Linux & FOSS, and show them you don’t need to be a pro to start using it
  • guiding people trough the sea of alternatives for proprietary software such as MS Office, Live Messenger, Photoshop, Publisher, Windows Media Player, Picture managers,…
  • help people getting Ubuntu installed on their laptop if they bring one along
  • show each-other nice tweaks you’ve got up your sleeves or admire the work of others
  • demo’s on how to use Ubuntu in an efficient way
  • introducing people to the Ubuntu-be LoCo-team! Let them know what we do, how they benefit & help.
  • hand out Ubuntu cd’s Continue reading Jaunty Release-Party Ghent 09/05