In case you need to draw a diagram from time to time, you should think about Dia. Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.

It is a very nice replacement for Visio which is commercial product. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.

It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages).

I almost bought LanFlow for 99$ but then I found Dia . The next step is donation to this project

Here is the link http://live.gnome.org/Dia

Icons are just fine… No need for repeating text labels…

I usually don’t like a stickers on the notebooks. Especially the large one which after some time became dirty and ugly. Also, it isn’t very nice to open your laptop on the presentation in front of the 200 attendees while the laptop looks a like teenage room with posters on the wall.

That is the main reason why I always keep my laptop nice and clean.

But I changed my mind a few days ago when I heard about unixs tickers.com project. The main idea behind this project is to test the Linux user’s interest in customizing pc and notebook case with a sticker of a favorite distribution.

The stickers are small and nice so I didn’t wait to much before I decided to create an order. Two days ago I received them

Sorry for the bad image quality (the image is made with my phone because the Canon camera is not at home ). You can see that stickers are very nice and small so they fits perfectly. Another good idea behind this project is that every time when someone buys Linux Mint sticker, they donate 0.10€ to Mint Linux project.

Very very nice idea

I forget to say that price is very nice – only 0,45€ for one sticker. The link is HERE.

EDIT 4th Feb 2012.

As you can see from the comments below, this project is probably dead. The link will lead you to the parked domain and I’m not sure why. To avoid any problems I may have, I broke all links inside this post because I don’t want to create a negative advert.

To save your time here is the whois output for unix stickers.com domain

Registrant:
   stefano di luca
   viale filiani 14
   pineto, teramo 64025
   Italy
 
   Registered through: Go Daddy
   Domain Name: UNIXSTICKERS.COM
      Created on: 16-Mar-08
      Expires on: 16-Mar-12
      Last Updated on: 24-Jan-12
 
   Administrative Contact:
      di luca, stefano  stef.il@gmail.com
      viale filiani 14
      pineto, teramo 64025
      Italy
      (085) 949-0560
 
   Technical Contact:
      di luca, stefano  stef.il@gmail.com
      viale filiani 14
      pineto, teramo 64025
      Italy
      (085) 949-0560
 
   Domain servers in listed order:
      NS1.FASTPARK.NET
      NS2.FASTPARK.NET

In case you didn’t received your stickers (and you already sent a payment), try to contact the domain owner via posted email or open dispute process on PayPal.

Patent related suits between mobile device/components manufacturers

Taking care about disk usage is a very good habit. There are several options for this and now I will only describe df and du commands.

The df utility displays the disk space usage on all mounted filesystems.

[root@abc ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                      35772016  20297132  13628408  60% /
/dev/sda1               101086     17692     78175  19% /boot
tmpfs                   513044         0    513044   0% /dev/shm

Adding the -T option (type) will print the filesystem type. Also, the good idea is to add -h option because df measures the size in 1K blocks, which is difficult for a desktop user to recalculate.

Now we have

[root@abc ~]# df -h -T
Filesystem    Type    Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
              ext3     35G   20G   13G  60% /
/dev/sda1     ext3     99M   18M   77M  19% /boot
tmpfs        tmpfs    502M     0  502M   0% /dev/shm

As you can see, it is much easier to understand.

You can use the du command to determine which files or directories need to be deleted or reduced. A simple du will print usage for the present working directory and its subdirectories, along with the size of each directory.

du directory will print the size of an particular dir.

Avilable options:
-h – print the size of the podcasts directory in a more readable format
-c – prints the grand total size of the directory at the end.
-a – displays the file names along with directories
-s – display a summary, without showing all of the subdirectories.

For example, du -ch | grep total prints just one line with the total size of the directory.

Thanks but no thanks…

Few days ago I had a failure with my computer. The Windows installation on C partition decided to die. It was impossible to recover it and the only solution was to backup my emails, desktop and my documents, then format.

Luckily I had a dual boot with Mint Linux and it was extremely easy to backup my files… Also, like I said a few days ago, I became a father and the whole day was like the days before… Tea is very nice baby and she had a very nice schedule (eat, sleep, dump) and yesterday was the same. While I was in “the father loop” I decided to abandon Windows XP.

The reasons:

• it is an old OS and Win 7 works much better
• I’m lazy and I don’t have enough time to reinstall it. I will keep the Win XP license sticker just like a note that I had a Win XP on this notebook.

What exactly do I need from my computer:

• LAMP (done)
• Winbox (done via Wine)
• Netbeans, Eclipse (they work better on Linux)
• MySQL workbench (it works perfectly on Linux)
• Putty, Pidgin, Skype, XChat, Firefox, Chrome, Thunderbird, … (done)
• Photoshop (Gimp can be used for the basic image manipulation. I already gave up from my professorial photography career so I can live without Photoshop)
• Corel (maybe Inkscape can be a replacement… I’m still not sure…I didn’t use Corel for years and I don’t need it at all.)
• TrueCrypt (it works fine)

Three days after I switch to Linux, I’m still trying to forget on Windows. For now, I’m doing well.

Don’t worry… I still didn’t forget on FreeRadius howtos. I’m working on the next post about Freeradius and MySQL. Also, I have a few tricks which you should consider in case you want to tune your MySQL and FreeRadius.

Best regards

Edit:

Ten days later, I’m still struggling.

This post won’t be long… Actually I became a father 20 days ago and this blog will be “on hold” until I find some time.

This is my first child and the feeling is GREAT. The baby girl and the mother are fine and all we’re actually doing is a some kind of loop “eat-sleep-dump”..

See ya later fellas…

Few days ago one client called and asked about high CPU load on his Fedora server…
It was very easy to detect that CPU is consumed by kipmi0 process. Unfortunately classic commands kill, pkill, kill -9, … didn’t help.

The problem was in loaded modules (lsmod command)

ipmi_si 38349 0
ipmi_msghandler 32665 1 ipmi_si

I didn’t have enough time to investigate about this but simple rmmod ipmi_msghandler and rmmod ipmi_si was enough to solve this problem. Well I was wrong that this will solve the problem… After reboot it was all like before… The modules are still here and kipmi0 process was too aggressive…

Searching on Google about this problem didn’t help a lot. After some digging, I found out that the lm_sensors is responsible for loading these modules.

nano /etc/sysconfig/lm_sensors gave me the answer. At the end, there are few lines

MODULE_0=ipmi-si
MODULE_1=ipmisensors
MODULE_2=coretemp

Commenting those lines was enough to solve this problem. I suppose that this server is too old (Fedora 6) and some incompatibility exists between hardware platform and those modules…

If you have any info about this problem, please drop a comment so we can all learn something…

FreeRADIUS is the most widely deployed RADIUS server in the world. It is the basis for multiple commercial offerings. It supplies the AAA needs of many Fortune-500 companies and Tier 1 ISPs. In this post I will try to describe basic installation and config options (at least some of them). The biggest problem for me was the lack of documentation and it was very hard to learn something about it when the latest book about Radius was published 8 years ago.

Where possible, I recommend using the packaging system that is used for your distro. The version that is supplied might be out of date, but it is likely to work “out of the box”.

RPM packages

FreeRADIUS is distributed on Fedora/RHEL/CentOS systems as a set of RPM packages. There is a main package called “freeradius” and several subpackages whose name is “freeradius-XXX” where XXX is optional functionality. For example the support needed for MySQL database backend will be found in the package “freeradius-mysql”.

On CentOS and Red Hat, “yum install freeradius” will install FreeRadius 1.1.3 which is a several years old version. Better option is to install FreeRadius 2.x with yum install freeradius2. Please see the notes above about optional packages. Also, keep in mind that all config files will be installed in /etc/raddb. More info can be found HERE.

More info about RPM versions can be found Here (Thanks J. Dennis).

[root@ms ~]# yum search freeradius
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * addons: mirror.centos.com.ba
 * base: mirror.centos.com.ba
 * extras: mirror.centos.com.ba
 * rpmforge: ftp-stud.fht-esslingen.de
 * updates: mirror.centos.com.ba
Excluding Packages in global exclude list
Finished
====================== Matched: freeradius ===================================
freeradius.x86_64 : High-performance and highly configurable free RADIUS server.
freeradius-mysql.x86_64 : MySQL bindings for freeradius
freeradius-postgresql.x86_64 : postgresql bindings for freeradius
freeradius-unixODBC.x86_64 : unixODBC bindings for freeradius
freeradius2.x86_64 : High-performance and highly configurable free RADIUS server
freeradius2-krb5.x86_64 : Kerberos 5 support for freeradius
freeradius2-ldap.x86_64 : LDAP support for freeradius
freeradius2-mysql.x86_64 : MySQL support for freeradius
freeradius2-perl.x86_64 : Perl support for freeradius
freeradius2-postgresql.x86_64 : Postgresql support for freeradius
freeradius2-python.x86_64 : Python support for freeradius
freeradius2-unixODBC.x86_64 : Unix ODBC support for freeradius
freeradius2-utils.x86_64 : FreeRADIUS utilities

More info about basic settings will be shown later.

Install from source

Download the latest FreeRadius from this link. (Current version is 2.1.10)

# wget ftp://ftp.freeradius.org/pub/freeradius/freeradius-server-2.1.10.tar.gz
# tar xvzf freeradius-server-2.1.10.tar.gz
# cd freeradius-server-2.1.10
# ./configure

It is very likely that config process will fail for some reasons. To fix this, search WARNINGS lines and install the missing rpms (yum install libtood-ltdl libtool-ltdl-devel is required).

# make
# make install

This is a default installation and all config files will be located in /usr/local/etc/raddb and you should find the next files inside

[root@ms raddb]# ls -la
total 220
drwxr-xr-x 7 root root  4096 Jan 27 15:54 .
drwxr-xr-x 4 root root  4096 Jan 27 15:53 ..
-rw-r----- 1 root root   671 Jan 27 15:54 acct_users
-rw-r----- 1 root root  4174 Jan 27 15:54 attrs
-rw-r----- 1 root root   513 Jan 27 15:54 attrs.access_challenge
-rw-r----- 1 root root   458 Jan 27 15:54 attrs.access_reject
-rw-r----- 1 root root   437 Jan 27 15:54 attrs.accounting_response
-rw-r----- 1 root root  2022 Jan 27 15:54 attrs.pre-proxy
drwxr-x--- 2 root root  4096 Jan 27 15:54 certs
-rw-r----- 1 root root  6703 Jan 27 15:54 clients.conf
-rw-r----- 1 root root   883 Jan 27 15:54 dictionary
-rw-r----- 1 root root 18063 Jan 27 15:54 eap.conf
-rwxr-xr-x 1 root root  4744 Jan 27 15:54 example.pl
-rw-r----- 1 root root 12722 Jan 27 15:54 experimental.conf
-rw-r----- 1 root root  2352 Jan 27 15:54 hints
-rw-r----- 1 root root  1604 Jan 27 15:54 huntgroups
-rw-r----- 1 root root  3218 Jan 27 15:54 ldap.attrmap
drwxr-x--- 2 root root  4096 Jan 27 15:54 modules
-rw-r----- 1 root root  2840 Jan 27 15:54 policy.conf
-rw-r----- 1 root root  4873 Jan 27 15:54 policy.txt
-rw-r----- 1 root root   984 Jan 27 15:54 preproxy_users
-rw-r----- 1 root root 26529 Jan 27 15:54 proxy.conf
-rw-r----- 1 root root 27238 Jan 27 15:54 radiusd.conf
drwxr-x--- 2 root root  4096 Jan 27 15:54 sites-available
drwxr-x--- 2 root root  4096 Jan 27 15:54 sites-enabled
drwxr-x--- 7 root root  4096 Jan 27 15:54 sql
-rw-r----- 1 root root  3042 Jan 27 15:54 sql.conf
-rw-r----- 1 root root  2475 Jan 27 15:54 sqlippool.conf
-rw-r----- 1 root root  3597 Jan 27 15:54 templates.conf
-rw-r----- 1 root root  6524 Jan 27 15:54 users

The default configuration is designed to work everywhere, and to provide nearly every authentication method. Do not edit the default configuration files until you understand what they do. This means reading the documentation contained in the comments of the configuration files.

When the server has been installed on a new machine, the first step is to start it in debugging mode, as user root:

# radiusd -X

This step demonstrates that the server is installed and configured properly. If you have installed Version 2 from source, this step will also create the default certificates used for EAP authentication. If everything went OK, you should see the lines

......
Listening on authentication address * port 1812
Listening on accounting address * port 1813
Listening on command file /usr/local/var/run/radiusd/radiusd.sock
Listening on authentication address 127.0.0.1 port 18120 as server inner-tunnel
Listening on proxy address * port 1814
Ready to process requests.

To stop freeradius press Ctrl+C.

Thats all for now… In next few days I will add more articles about FreeRadius.