Author Archives: cviorel - Page 9

Sample firewall script for Ubuntu

Posted by on May 7, 2008 No comments | This post has 1,081 views.

I just thought that you might be interested in a small script you can use in Hardy Heron.

It uses the new UFW (Uncomplicated firewall) introduced in this new Ubuntu distro.

The script is well commented, so everything is easy to understand.

Here is the script:

You can modify it by adding/removing rules accordingly.

Backup your MySQL databases automatically with AutoMySQLBackup

Posted by on May 6, 2008 No comments | This post has 742 views.

If you are a MySQL user and you want to have a disaster recovery solution, or even as a simple backup, you can write small shell scripts based on mysqldump tool.

For this, you need AutoMySQLBackup. It doesn’t have any real requirements (mysqldump of course is needed – in any mysql client package – and gzip or bzip2 to compress the resulting file) and has all the features I was looking for in such a script.

AutoMySQLBackup has all the features I needed: it can backup a single database, multiple databases, or all the databases on the server; each database is saved in a separate file that can be compressed (with gzip or bzip2); it will rotate the backups and not keep them filling your hard drive (as normal in the daily backup you will have only the last 7 days of backups, the weekly if enabled will have one for each week, etc.). It has also some other features (check the project homepage for full details), that I am not using myself (like email logs for example), but other peoples might find interesting.

All you have to do is to modify a few things:

# Username to access the MySQL server e.g. dbuser
USERNAME=dbuser
# Username to access the MySQL server e.g. password
PASSWORD=password
# Host name (or IP address) of MySQL server e.g localhost
DBHOST=localhost
# List of DBNAMES for Daily/Weekly Backup e.g. "DB1 DB2 DB3"
DBNAMES="all"
# Backup directory location e.g /backups
BACKUPDIR="/var/backup/mysql"
# Mail setup
MAILCONTENT="quiet"

You can run the script manually but you will want to enable it in cron
and run daily.

Enabling Temperature Sensors in Ubuntu

Posted by on April 4, 2008 No comments | This post has 1,034 views.

Most computers these days come with a myriad of sensors to monitor the temperature of your computer. These sensors are generally located on the processor and the motherboard, and you might also have sensors on your video card. On top of that, all S.M.A.R.T-enabled hard drives have built-in temperature monitoring.
I can show you the steps to enable the temperature sensors in your computer in Ubuntu, or any other version of Linux.
1. Installing the sensor libraries
First thing’s first – you need to install the libraries that allow Linux to read your sensors. To do this, install the lm-sensors library, by running the command:
sudo apt-get install lm-sensors
This will install the libraries for your motherboard’s sensors. For your hard-disk sensors, you’ll want to install hddtemp:
sudo apt-get install hddtemp
In Ubuntu, the install will ask you several questions. Do not be scared, the default settings should work.

2. Running sensors-detect
Now that your sensor libraries are installed, you need to detect your sensors! Run the command:
sudo sensors-detect
Which will probe your system for sensors. Answer “YES” to all questions! Don’t just hit enter, type “YES”, because at the end there will be a question for which the default answer is “no”, and we’ll want to answer in the affirmative.
You willbe asked, at some point, “Do you want to add these lines to /etc/modules automatically? (yes/NO)” This is the question we want to make sure we answer YES to.

3. Loading the modules
Since we answered YES to the previous question, our sensor modules will be loaded by default the next time we start up. But since we don’t want to have to reboot, we’re going to use the information we got from the sensors-detect script to load the modules ourselves, this time only. Right above the last question will appear a list of modules that you should load, in the form of:

#—-cut here—-
# Chip drivers
smsc47m1
#—-cut here—-

You may have more, or different, items listed – that’s fine! What we want to do now, to load these modules, is use the modprobe command, as follows:
sudo modprobe [module name]

4. Monitoring the sensors!
Wow, that was a lot of work! Now, let’s see the rewards. On the command line, you can simply run:
sensors

However, we’d rather have a graphical interface for checking up on our hardware, so let’s install an applet for our Gnome desktop to keep an eye on our system’s temperature. Run the command:
sudo apt-get install sensors-applet
to install the applet. Now, add the applet by right-clicking on your desktop panel, selecting “Add to Panel,” and you will now see a “Hardware Sensors Monitor” applet in the System & Hardware section. Click and drag this to your panel to add it.

My experience with Ubuntu 8.04 Hardy Heron Beta

Posted by on April 3, 2008 No comments | This post has 588 views.

After a few tests with the new beta from Ubuntu, I decided to write some of my thoughts about this release.
Please note that this is a BETA release, has many unresolved bugs and needs to be polished before the final release.
Overall, everything seems better. A new host-based firewall application, the new Vinagre VNC client, Firefox 3 Beta 4 replaces Firefox 2 as the default browser, PulseAudio is now enabled by default, PolicyKit is now integrated in the administrative user interfaces, linux kernel 2.6.24, Xorg 7.3, GNOME 2.22, a few new compiz plugins.
In my opinion, there is a downside in this release regarding the PulseAudio sound server. Some non-GNOME applications still need to be changed to output to pulse/esd by default and the volume control tools are not yet integrated. Users with Audigy1 sound cards will be suprised to find out that the 5.1 output is not so good as it was in ALSA. It will be very difficult for a beginner to configure by hand the audio for best results in sound quality.
Anyway, many of this bugs will be resolved until the final release. Can’t wait!

XMMS, Audacious, BMP equalizer presets

Posted by on March 4, 2008 4 comments | This post has 1,739 views.

When using XMMS, Audacious or BMP on Linux, some of you miss the equalizer presets from Winamp.
This is how you can get them in your linux distribution.
Write a shell script or just run these commands in your terminal:

The script will activate presets for XMMS, Audacious and BMP. If you don’t use all of them, feel free to remove the appropriate line.

xmms_presets

Have fun!

HOWTO make DVD and CD .iso images using dd or cat in Linux

Posted by on March 4, 2008 No comments | This post has 808 views.

Please note that making security backups of your DVD/CD:s may be illegal in your country.

for the purpose of making these backups, the programs you need are standard, *NIX programs, and it is a safe bet that you wont need to install anything.
You may also need to have root permissions in able for you to access the DVD or CD devices.

Heres how to back up the device:

with cat:

with dd:

replace /dev/dvd0 with what ever device it is corresponding with your CD/DVD rom player. If you’re unsure, you might find that $ cat /etc/fstab might provide you some useful information.

The two commands above copies the CD rom or DVD to the home folder. Making a image file with the iso 9660 or the Universal Disk Format file system. Please note that neither cat nor dd cares about file system. Dd copies blocks, and cat prints a file to stdout.

I have heard that cat does not copy the mbr record of the devices copied with it, but I know that dd does.

Note that if you’ve made the image file as the root user, you might have to chmod the file, and it might also be nice to change the files ownership

how to loopback mount the .iso file:

replace iso9660 with udp if your mounting a dvd image.

and how to umount it:

or

Ubuntu brainstorm launched!

Posted by on February 29, 2008 No comments | This post has 709 views.

Ubuntu now has its own Brainstorm website where people can add their ideas and vote for their favorites.
http://brainstorm.ubuntu.com/

Unp

Posted by on February 20, 2008 No comments | This post has 579 views.

Unp is a small perl script which makes extraction of any archive files a bit easier. It support several compressors and archiver programs, chooses the right one(s) automatically and extracts one or more files in one go.

Instalation:
sudo apt-get install unp

Usage:
usage: unp file [file]...
file: compressed file(s) to expand

Use -- to pass arguments to external programs, eg. some tar options:
unp fastgl.tgz xmnt.tgz -- -C /tmp

Special option:
-f Continue even if program availability checks fail
-u For Debian packages:
- extract data.tar.gz after each operation
- extract control.tar.gz in control//
For other archives:
- create directory /
- extract contents there

currently supported extensions and formats are
tar[.gz,.bz2], gz, bz2, Z, ar/deb, rpm, shar, rar, arj, zip, LHa, cab, ace,
tnef, uu (mail, news), mime, hqx, sea, zoo, pmd, cpio, afio, lzop

Problem:
It doesn’t extract files from RAR archives with full path!