Category Archives: Linux

Enabling remote desktop on a VirtualBox Machine

To enable remote desktop on a VirtualBox machine, you have to follow these steps:
VBoxManage modifyvm MachineName -vrdp
This command enables rdp on the virtual machine
VBoxManage startvm MachineName -type vrdp

It starts virtual machine, listening for rdp request on port 3389 (default port)
rdesktop-vrdp localhost

Connects virtual machine with rdp (You can use rdesktop too).
If you want to change rdp port, use this command:
VBoxManage modifyvm MachineName -vrdpport

Also, enabling authentication for rdp is possible:
VBoxManage modifyvm MachineName -vrdpauthtype null | external | guest

VBoxManage is the command line interface of the VirtualBox.
You can make these settings with GUI: Settings -> Remote Display -> Enable VRDP Server
If you want to use your virtual machine with vrdp only, you can use this command simply:
VBoxHeadless -startvm MachineName

Note: RDP server is not included in Open Source Edition of the VirtualBox. If you want to use this feature, you have to use closed-source edition.

Using iPhone internet sharing over bluetooth under Linux

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To use your iPhone’s internet connection through a Linux notebook over bluetooth, you have to open Tethering option on your iPhone device, under the Settings->General->Network section.

After that you can install Blueman (a simple and intuitive bluetooth manager) for easily configuring bluetooth PAN network:

apt-get install blueman

Start blueman-manager and find your mobile device and connect to it. When connection completed successfully, select Device->Add->Network Access Point in blueman-manager.
And the last step, configure the network interface:

dhclient bnep

Logwatch on Ubuntu Desktop/Server

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Logwatch is an Ubuntu modular log analyzer that runs every night and mails you the results. It can also be run from command line. The output is by service and you can limit the output to one particular service. The subscripts which are responsible for the output, mostly convert the raw log lines in structured format.
Logwatch generally ignores the time component in the output, that means, you will know that the reported event was logged in the requested range of time, but you will have to go to the raw log files to get the exact details.
Install logwatch using the following command:

sudo apt-get install logwatch

This will install all the required packages

Configuring Logwatch:

first you need to make sure you server is able to send the mails outside you can do this using postfix with SMTP server configuration.

Now you need to edit logwatch.conf file:

sudo nano /usr/share/logwatch/default.conf/logwatch.conf

Change the following information:

Output = mail
Format = html
MailTo = test@gmail.com

Save and exit the file

If you want to know more available options check logcheck manpage using the following command from your terminal:

man logcheck

Now edit the 00logwatch file

sudo nano /etc/cron.daily/00logwatch

add the following line:

/usr/sbin/logwatch –mailto test@gmail.com

Save and exit the file

This tool is very useful, give it a try!

Maximize internet speed connection in Ubuntu via sysctl

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Do you want to maximize your bandwidth? Here are few important settings you should do to speed up your internet and it works in Ubuntu and all Linux operating system via sysctl.
First open a Terminal via Applications->Accessories->Terminal
Type:

sudo gedit /etc/sysctl.conf

Then Paste the Following at the end of the file:

# increase TCP max buffer size setable using setsockopt()
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
# increase Linux autotuning TCP buffer limits
# min, default, and max number of bytes to use
# set max to at least 4MB, or higher if you use very high BDP paths
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
# don’t cache ssthresh from previous connection
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
# recommended to increase this for 1000 BT or higher
net.core.netdev_max_backlog = 2500
# for 10 GigE, use this, uncomment below
# net.core.netdev_max_backlog = 30000
# Turn off timestamps if you’re on a gigabit or very busy network
# Having it off is one less thing the IP stack needs to work on
#net.ipv4.tcp_timestamps = 0
# disable tcp selective acknowledgements.
net.ipv4.tcp_sack = 0
#enable window scaling
net.ipv4.tcp_window_scaling = 1

Press Ctrl-S to save, then alt-F4 to exit and then type:

sudo sysctl -p

to apply the settings.

Now, check your speed using speed-test site or download files in the net.

You can disable all these settings by removing these lines you added via:

sudo gedit /etc/sysctl.conf

Open Source tools and applications for web developers

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Several open source tools have evolved in the past and have become popular with the developers too. These tools have gained popularity not only because they come free but because of the ease to work with and the features. First let us see some code editors:

– Aptana: It is a free, JavaScript focused development environment, cross-platform and open source for building Ajax applications. It supports HTML, JavaScript, CSS languages, FTP/SFTP and has a powerful JavaScript debugger that can help in troubleshooting your code.

– Eclipse : It is an open source software framework written mainly in Java. It is an integrated development environment consisting Java development toolkit (JDK) and compiler (ECJ) for developing applications in Java. Developers can extend its capabilities by installing plug-ins such as development toolkits for other programming languages written specifically for eclipse software framework. Language packs for over a dozen languages are available.

– JEdit : It is a programmer’s text editor which has many hundreds of man-hours of development behind it. It is a java-based solution and a cross-platform product which can work on many operating systems like Windows, VMS, UNIX, OX/2 and Mac OS X.

– NVU : It is a web authoring system for Linux desktop users, Macintosh users as well as for Microsoft windows and is a competitor for similar products like Dreamweaver and Frontpage. Nvu actually means new view and makes managing a website very easy. Now even people without knowledge of HTML or technical expertise can create web pages and manage a website.

– Quanta Plus : It is a web development environment with a lot of features and is highly stable. Quanta has a vision of achieving maximal user extensibility through the best architectural foundations, best, efficient design and natural use of code.

We shall see other tools in other posts.

Ubuntu to Windows XP folder sharing

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Computer networks are sometimes comprised of various methods, and while operating a network made up fully of Ubuntu desktop and server computer systems would definitely be enjoyable, some community environments must consist of both Ubuntu and Microsoft Windows systems working collectively in harmony.
When making an Ubuntu shared folder that was created with NTFS be accessible to Windows XP steps. Run the NTFS configuration tool on the drive.
It is advisable have admin rights to do that modification.
Select: Application –> Accessories –>Terminal
then type the following:

sudo gedit /etc/samba/smb.conf

In the [global] section, add the following line:

usershare proprietor only = false

Some Linux security tips for Rootkit Hunter

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If you run Rootkit Hunter and you haven’t modified your stock Red Hat configuration of the SSH service (sshd), chances are it will find that you allow root logins. Rootkit Hunter considers these as possible security risks. However, to fix this, you can simply login as root, fire up a text editor, and edit the file

/etc/ssh/sshd_config

Make the following changes:
You’ll find a commented line like this:
#Protocol 2,1
Uncomment it and change it to:
Protocol 2
This will disallow logins using the older versions of the protocol

Look for the commented line
#PermitRootLogin yes
Uncomment the line and change it so it reads:
PermitRootLogin no
This will configure sshd NOT to allow root logins.

After this, be sure to restart sshd (assuming you run the service in the first place so:
Service sshd restart

By the way Rootkit scanner is scanning tool to ensure you for about 99.9% you’re clean of nasty tools. This tool scans for rootkits, backdoors and local exploits.

2010 in review – Not bad…

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The stats helper monkeys at WordPress.com mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health:

Healthy blog!

The Blog-Health-o-Meter™ reads Wow.

Attractions in 2010

These are the posts and pages that got the most views in 2010.

Upload, store and download files with no limits! (up to 2GB single file, no space or time limitations) December 2010

How to unzip and install a tar.gz file in Linux October 2006
76 comments

SoundConverter: the best (and the simpliest) audio converter for Ubuntu! August 2007
8 comments and 1 Like on WordPress.com,

Linux August 2006
124 comments

How to add a cool “MAC OS X” dock in your Linux: two different solutions for Kubuntu. May 2007
6 comments

Get Kindle for PC to Ubuntu (if you really don’t like Calibre)

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Amazon’s Kindle a popular portable e-book reader device, lately made Kindle for PC application that allows you to download and have books on your computer rather than having a portable e-book reader device. There’s only Kindle Windows version but the nice thing is you can have this application in Linux.
This is tested in Ubuntu 9 running Gnome. You can use different version of Linux, but first you must have Wine HQ installed to you computer. Then download the EXE file of Kindle for PC application in Amazon.
Install this with Wine HQ software loader and proceed to the normal installation, the same thing that you do in Windows environment.
Note:

– At your first run you won’t see anything at all

– Configure Wine first and add Kindle for PC as an application and make it run in Windows 98 mode

– If it won’t work, change to other mode

– When it opens successfully you have to input you Amazon email add and password to register the software.

But, please, don’t forget that if you prefer open source software, you can directly use Calibre, a powerful free software we posted a while ago.

LibreOffice vs. OpenOffice! What’s the difference?

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Since the end of September 2010, a group of German OpenOffice volunteers left definitively the project to join the The Document Foundation and develop a fork version of the famous free productivity platform now controlled by Oracle. After just few months we have LibreOffice: a (more or less) new cross-platform productivity software based on OpenOffice version 3.3 beta. We compared both the free suites and apparently we did not notice particular differences in features and tools. Also the graphic interface is similar between the two platforms and the buttons position is the same. At the moment LibreOffice supports less languages in its Linux and MAC OS X versions and it is not compatible with Solaris based PCs. Both the productivity platforms are able to use the OpenOffice extension library. Consequently, it is clear that it’s too early to notice relevant technical differences between the two competitors but, for sure, something will show off in the next versions. In fact LibreOffice has been created to guarantee a vendor independent office suite which can be developed with no copyright software chunks. The goal is prestigious and we can only say, Good Luck LibreOffice!