Posts Tagged ‘noah’

Upgrade Debian Linux 9 to 10 Stretch to Buster and Disable graphical service load boot on Debian 10 Linux / Debian Buster is out

Tuesday, July 9th, 2019

howto-upgrade-debian-linux-debian-stretch-to-buster-debian-10-buster

I've just took a time to upgrade my Debian 9 Stretch Linux to Debian Buster on my old school Laptop (that turned 11 years old) Lenovo Thinkpad R61 . The upgrade went more or less without severe issues except few things.

The overall procedure followed is described n a few websites out there already and comes up to;

 

0. Set the proper repository location in /etc/apt/sources.list


Before update the sources.list used are:
 

deb [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster main contrib non-free
deb-src [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster main contrib non-free

 

deb [arch=amd64,i386] http://security.debian.org/ buster/updates main contrib non-free
deb-src [arch=amd64,i386] http://security.debian.org/ buster/updates main contrib non-free

deb [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster-updates main contrib non-free
deb-src [arch=amd64,i386] http://ftp.bg.debian.org/debian/ buster-updates main contrib non-free

deb http://ftp.debian.org/debian buster-backports main


For people that had stretch defined in /etc/apt/sources.list you should change them to buster or stable, easiest and quickest way to omit editting with vim / nano etc. is run as root or via sudo:
 

sed -i 's/stretch/buster/g' /etc/apt/sources.list
sed -i 's/stretch/buster/g' /etc/apt/sources.list.d/*.list

The minimum of config in sources.list after the modification should be
 

deb http://deb.debian.org/debian buster main
deb http://deb.debian.org/debian buster-updates main
deb http://security.debian.org/debian-security buster/updates main

Or if you want to always be with latest stable packages (which is my practice for notebooks):

deb http://deb.debian.org/debian stable main
deb http://deb.debian.org/debian stable-updates main
deb http://security.debian.org/debian-security stable/updates main

 

1. Getting list of hold packages if such exist and unholding them, e.g.

 

apt-mark showhold


Same could also be done via dpkg

dpkg –get-selections | grep hold


To unhold a package if such is found:

echo "package_name install"|sudo dpkg –set-selections

For those who don't know what hold package is this is usually package you want to keep at certain version all the time even though after running apt-get upgrade to get the latest package versions.
 

2. Use df -h and assure you have at least 5 – 10 GB free space on root directory / before proceed

df -h /

3. Update packages list to set new set repos as default

apt update

 

4. apt upgrade
 

apt upgrade

Here some 10 – 15 times you have to confirm what you want to do with configuration that has changed if you're unsure about the config (and it is not critical service) you're aware as such as Apache / MySQL / SMTP etc. it is best to install the latest maintainer version.

Hopefully here you will not get fatal errors that will interrupt it.

P.S. It is best to run apt-update either in VTTY (Virtual console session) with screen or tmux or via a physical tty (if this is not a remote server) as during the updates your GUI access to the gnome-terminal or konsole / xterm whatever console used might get cut. Thus it is best to do it with command:
 

screen apt upgrade

 

5. Run dist-upgrade to finalize the upgrade from Stertch to Buster

 

Once all is completed of the new installed packages, you will need to finally do, once again it is best to run via screen, if you don't have installed screen install it:

 

if [ $(which screen) ]; then echo 'Installed'; else apt-get install –yes screen ; fi

screen apt dist-upgrade


Here once again you should set whether old configuration to some e services has to stay or the new Debian maintainer package shipped one will overwrite the old and locally modified (due to some reason), here do wisely whatever you will otherwise some configured services might not boot as expected on next boot.

 

6. What if you get packages failed on update


If you get a certain package failed to configure after installed due to some reason, if it is a systemd service use:

 

journalctl -xe |head -n 50


or fully observer output of journalctl -xe and decide on yourself.

In most cases

dpkg-reconfigure failed-package-name


should do the trick or at least give you more hints on how to solve it.

 

Also if a package seems to be in inconsistent or broken state after upgrade  and simple dpkg-reconfigure doesn't help, a good command
that can help you is

 

dpkg-reconfigure -f package_name

 

or you can try to workaround a failed package setup with:
 

dpkg –configure -a

 
If dpkg-reconfigure doesn't help either as I experienced in prior of Debian from Debian 6 -> 7 an Debian 7 ->8 updates on some Computers, then a very useful thing to try is:
 

apt-get update –fix-missing 

apt-get install -f


At certain cases the only work around to be able to complete the package upgrade is to to remove the package with apt remove but due to config errors even that is not possible to work around this as final resort run:
 

dpkg –remove –force-remove-reinstreq

 

7. Clean up ununeeded packages

 

Some packages are left over due to package dependencies from Stretch and not needed in buster anymore to remove them.
 

apt autoremove

 

8. Reboot system once all upgrade is over

 

/sbin/reboot

 

9. Verify your just upgraded Debian is in a good state

 

root@noah:~# uname -a;
Linux noah 4.19.0-5-rt-amd64 #1 SMP PREEMPT RT Debian 4.19.37-5 (2019-06-19) x86_64 GNU/Linux

 

root@noah:~# cat /etc/issue.net
Debian GNU/Linux 10
 

 

root@noah:~# lsb_release -a
No LSB modules are available.
Distributor ID:    Debian
Description:    Debian GNU/Linux 10 (buster)
Release:    10
Codename:    buster

 

root@noah:~# hostnamectl
   Static hostname: noah
         Icon name: computer-laptop
           Chassis: laptop
        Machine ID: 4759d9c2f20265938692146351a07929
           Boot ID: 256eb64ffa5e413b8f959f7ef43d919f
  Operating System: Debian GNU/Linux 10 (buster)
            Kernel: Linux 4.19.0-5-rt-amd64
      Architecture: x86-64

 

10. Remove annoying picture short animation with debian logo looping

 

plymouth-debian-graphical-boot-services

By default Debian 10 boots up with annoying screen hiding all the status of loaded services state .e.g. you cannot see the services that shows in [ FAILED ] state and  which do show as [ OK ] to revert back the old behavior I'm used to for historical reasons and as it shows a lot of good Boot time debugging info, in previous Debian distributions this was possible  by setting the right configuration options in /etc/default/grub

which so far in my config was like so

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash scsi_mod.use_blk_mq=y dm_mod.use_blk_mq=y zswap.enabled=1 text"


Note that zswap.enabled=1 passed option is because my notebook is pretty old machine from 2008 with 4GB of memory and zswap does accelerate performance when working with swap – especially helpful on Older PCs for more you can read more about zswap on ArchLinux wiki
After modifying this configuration to load the new config into grub the cmd is:
 

/usr/sbin/update-grub

 
As this was not working and tried number of reboots finally I found that annoying animated gif like picture shown up is caused by plymouth below is excerpts from Plymouth's manual page:


       "The plymouth sends commands to a running plymouthd. This is used during the boot process to control the display of the graphical boot splash."

Plymouth has a set of themes one can set:

 

# plymouth-set-default-theme -l
futureprototype
details
futureprototype
joy
lines
moonlight
softwaves
spacefun
text
tribar

 

I tried to change that theme to make the boot process as text boot as I'm used to historically with cmd:
 

update-alternatives –config text.plymouth

 
As after reboot I hoped the PC will start booting in text but this does not happened so the final fix to turn back to textmode service boot was to completely remove plymouth
 

apt-get remove –yes plymouth

How to install BlueJeans Video calls, sharing, Conference software on Debian / Ubuntu Linux – Convert RPM to DEB package with alien howto

Tuesday, August 28th, 2018

bluejeans-linux-logo

As I'm currently looking for ways to maximize my incomes without taking participation in 5 days week 8 hours schedule in a Big Corporation office job (which prooved for me to be a terrible slavery) I decided to give Free Lancing a try once again. 
Historically I have registrations in some of the most popular Free Lancing services Web platforms such as freelancer.com and upwork.com.
But none of them really was easy enough to handle as applying and winning a project there is usually a lot of headbanging into the walls and the platforms are full of clients that are looking for free lancers for short-term projects the work selection there required too much work, often projects offered there are seriously under-paid and its really hard to negotiate with many of the clients as they're unprofessional in the fields they're working (don't get me wrong I'm not saying many people are not very successful with this platforms, and that the platforms are not providing work for me I only say it is not really something to my liking …

In the mean time if you happen to read this article and looking for a High Quality Empoyee Cheap System Administrator or automation developmer, an IT counseling FreeLancer or a Ultra cheap WebHosting service in the European Union, I'll be very happy if you become my client.

Anyways … further on I decided to further experiment a little bit with other Free Lancing platforms (suggested by a friend Mitko Ivanov who helped me a lot with things and is continuing to help me over the last year ).

So following his kind suggestion I already tried one of the popular FreeLancing freeeup.com which is looking only for a best specialists into the fields of Marketing, Development, System Administration etc. but even though I tried hard with them the guys decided I am not matching there criteria for a the best 1% of all the people in the field of IT so my application for the platform was rejected twice over the last 1 month and a half.

Another similar new platform for free lancing that looks promising that I've learned about is toptal.com (there site Slogan is Hire FreeLance Talent from the Top 3%) so I went there and registered.

I had hit a road block there too as it seems, there website registration form was not tested enough with non-Windows operating systems with Mozilla Firefox and as it happens that I am using Debian GNU / Linux for my Desktop their drop-down menus was not working, just like some of the form on their website regular expression checks failed.

I've contacted the guys to inform them about their problems (and they kindly advised) I just give a try a registration with different browser (i.e. Google Chrome) which I immediately did and registratoin there was finally a success.
I have to say the new user application form registration of toptal also annoyed me with the stupid requirement to provide a picture in 1000px x 1000px but as this freelancing platform is still new and has way to go until it is established name in the field of freelancing such as upwork.com and I warmly excuse them.

Once registerered for them the user has to schedule an entry interview just like it goes with a standard company interview with a kind of Human Resources (HR) specialist and I guess some technical guys in order to evaluate on your value (Ha-Ha, someone else to determine your value is already crazy but all crazy employees do it still, of course I don't care as I well know that my value is much more than what they put on me).
The online interview once scheduled has to be done in a Web Meeting (Online Rooms) Platform called BlueJeans similar to Cisco WebEx (that is today heavily used in Corporate world in companies such as Hewlett Packard where we used it heavily, IBM, Concentrix etc.) and others Zoom, JoinMe GotoMeeting, HighFive.

As you could guess BlueJeans (which is by the way a Cloud based meeting software – yackes !) is planned to work mainly on Windows and Mac OS Operating Systems and even though there is a BlueJeans Linux version the provided binary is only for RedHat based linuxes in the RPM binary package format, so in order for me to participate in the scheduled meeting, I either had to port the package and install it on my Debian (what triggeted me to write this article or) use a Virtual Machine such as VirtualBox or VMWare running some kind of Windows OS such as Windows 8 / 10 etc.

Even though I have a Windows 10 OS testbed in a Virtualbox container, I preferred to not use it for BlueJeans and do it the hard way and install BlueJeans on my Debian 9.5 Stretch Linux.

That appeared to be a relatively easy process, so below is how I did it:

1. Download alien convertion (tool) that allows you to convert RPM -> deb, Slackware -> Deb and Linux Standard Base (LDB) packages to deb package format

 

noah:~# apt-get install –yes alien

 

2. Download latest BlueJeans version from BlueJeans website
 

As of time of writting this article the download link for bluejeans online conferencing software is here

 

noah:~# wget https://swdl.bluejeans.com/desktop/linux/1.36/1.36.9/bluejeans-1.36.9.x86_64.rpm

 

3. Convert bluejeans rpm package with alien

 

noah:~# alien –to-deb bluejeans-*.rpm
 

 

 

Warning: Skipping conversion of scripts in package bluejeans: postinst postrm preinst prerm
Warning: Use the –scripts parameter to include the scripts.
bluejeans_1.36.9-2_amd64.deb generated
root@jericho:/home/hipo/Свалени# dpkg -i bluejeans_*.deb
Selecting previously unselected package bluejeans.
(Reading database … 516203 files and directories currently installed.)
Preparing to unpack bluejeans_1.36.9-2_amd64.deb …
Unpacking bluejeans (1.36.9-2) …
Setting up bluejeans (1.36.9-2) …

 


4. Install the deb package as usual with dpkg tool

 

noah: ~# dpkg -i bluejeans_*.deb

 

By default BlueJeans were installed under directory /opt/bluejeans

 

 

noah:~# ls -al /opt/bluejeans/bluejeans-bin
-rwxr-xr-x 1 root root 72423392 Jun 14 02:31 /opt/bluejeans/bluejeans-bin*

 

5. Fix missing library links if such are present in order to make BlueJeans workable

Historically I have dealt with many Linux programs that are provided only in RPM package format and I knew that often once an RPM is converted to DEB with alien due to the package dependency differences on Redhats (CentOS / Fedora etc.) there are problems with missing libraries.

This time this was the case as well, so as usual right after install I did a check up with ldd (print shared object dependencies Linux command) to find out about missing libraries and one library appeared missing.

 

noah:~# ldd /opt/bluejeans/bluejeans-bin
    linux-vdso.so.1 (0x00007fffa2182000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fae95f5e000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fae95d5a000)
    libgtk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0 (0x00007fae95718000)
    libgdk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0 (0x00007fae95463000)
    libatk-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libatk-1.0.so.0 (0x00007fae9523d000)
    libpangocairo-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007fae95030000)
    libgdk_pixbuf-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007fae94e0c000)
    libcairo.so.2 => /usr/lib/x86_64-linux-gnu/libcairo.so.2 (0x00007fae94aef000)
    libpango-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007fae948aa000)
    libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007fae945f5000)
    libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007fae943b2000)
    libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007fae9415e000)
    libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fae93e48000)
    libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fae93b0a000)
    libXi.so.6 => /usr/lib/x86_64-linux-gnu/libXi.so.6 (0x00007fae938fa000)
    libnss3.so => /usr/lib/x86_64-linux-gnu/libnss3.so (0x00007fae935b1000)
    libnssutil3.so => /usr/lib/x86_64-linux-gnu/libnssutil3.so (0x00007fae93381000)
    libsmime3.so => /usr/lib/x86_64-linux-gnu/libsmime3.so (0x00007fae93154000)
    libplc4.so => /usr/lib/x86_64-linux-gnu/libplc4.so (0x00007fae92f4f000)
    libnspr4.so => /usr/lib/x86_64-linux-gnu/libnspr4.so (0x00007fae92d10000)
    libgconf-2.so.4 => /usr/lib/x86_64-linux-gnu/libgconf-2.so.4 (0x00007fae92adf000)
    libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007fae928ad000)
    libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007fae9269b000)
    libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007fae92495000)
    libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007fae9228b000)
    libXcomposite.so.1 => /usr/lib/x86_64-linux-gnu/libXcomposite.so.1 (0x00007fae92088000)
    libasound.so.2 => /usr/lib/x86_64-linux-gnu/libasound.so.2 (0x00007fae91d8a000)
    libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007fae91b87000)
    libXtst.so.6 => /usr/lib/x86_64-linux-gnu/libXtst.so.6 (0x00007fae91981000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fae91763000)
    libcap.so.2 => /lib/x86_64-linux-gnu/libcap.so.2 (0x00007fae9155d000)
    libudev.so.0 => not found
    libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007fae9130c000)
    libnotify.so.4 => /usr/lib/x86_64-linux-gnu/libnotify.so.4 (0x00007fae91104000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fae90d85000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fae909f2000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fae907db000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fae90421000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fae96166000)
    libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007fae9021d000)
    libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007fae8fe7f000)
    libpangoft2-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007fae8fc6a000)
    libfribidi.so.0 => /usr/lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007fae8fa53000)
    libXinerama.so.1 => /usr/lib/x86_64-linux-gnu/libXinerama.so.1 (0x00007fae8f850000)
    libXrandr.so.2 => /usr/lib/x86_64-linux-gnu/libXrandr.so.2 (0x00007fae8f645000)
    libXcursor.so.1 => /usr/lib/x86_64-linux-gnu/libXcursor.so.1 (0x00007fae8f43b000)
    libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007fae8f208000)
    libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fae8efea000)
    libpixman-1.so.0 => /usr/lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007fae8ed44000)
    libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fae8eb41000)
    libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fae8e919000)
    libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fae8e70b000)
    libthai.so.0 => /usr/lib/x86_64-linux-gnu/libthai.so.0 (0x00007fae8e501000)
    libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007fae8e2fa000)
    libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007fae8e0f1000)
    libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fae8de7f000)
    libplds4.so => /usr/lib/x86_64-linux-gnu/libplds4.so (0x00007fae8dc7b000)
    libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fae8da79000)
    libdbus-glib-1.so.2 => /usr/lib/x86_64-linux-gnu/libdbus-glib-1.so.2 (0x00007fae8d851000)
    libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007fae8d5c9000)
    libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007fae8d3a1000)
    libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007fae8d18a000)
    libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007fae8cf31000)
    libharfbuzz.so.0 => /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007fae8cc81000)
    libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fae8ca7d000)
    libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fae8c877000)
    libdatrie.so.1 => /usr/lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007fae8c66f000)
    liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fae8c449000)
    liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007fae8c22c000)
    libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007fae8bf10000)
    libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007fae8bcc1000)
    libgraphite2.so.3 => /usr/lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007fae8ba94000)
    libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007fae8b87d000)
    libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007fae8b65d000)

 


As I am on my notebook with Debian 9 and on Debian / Ubuntus and other Linuxes udevd daemon and connected libraries are long time existing, it was obvious the problems to dependencies are because of missing library links (or library version inconsistencies).

To find out what kind of libudev.so* are present I used slocate package (locate) command.

 

noah:~# locate libudev.so
/lib/i386-linux-gnu/libudev.so.1
/lib/i386-linux-gnu/libudev.so.1.6.10
/lib/x86_64-linux-gnu/libudev.so
/lib/x86_64-linux-gnu/libudev.so.1
/lib/x86_64-linux-gnu/libudev.so.1.6.10

 

Obviously the missing library libudev.so.0 was present under a different name so I give a try to just create a new symbolic link from libudev.so.1 to libudev.so.0 hoping that the libudev library version Blue Jeans was compiled against did not have a missing binary objects from the ones installed on my OS.

 

noah:~# ln -sf /lib/x86_64-linux-gnu/libudev.so.1 /lib/x86_64-linux-gnu/libudev.so.0

 

noah:~# ldd /opt/bluejeans/bluejeans-bin |grep -i 'not found'

 

Above command did not return any missing libraries, so I went further and executed it.

6. Go start BlueJeans and register a user or use the anonymous login to be ready for the scheduled online meting

… And, Guess, what it works! 🙂
 

 

noah:~# /opt/bluejeans/bluejeans-bin

 

To make it easy to remember to later start the binary under a familiar name, I've also created a link into

 

noah:~# ln -sf /opt/bluejeans/bluejeans-bin /usr/bin/bluejeans
 

 

 

noah:~#  sudo su – hipo
hipo@noah:~$ /usr/bin/bluejeans

 

bluejeans-video-conferencing-online-sharing-meeting-software-running-on-debian-gnu-linux-screenshot
 

How to enable Control Alt Backspace to Kill X server on Debian / Ubuntu Linux

Thursday, September 28th, 2017

kill-X-server-switch-revert-back-to-ctrl-alt-backspace-howto
Being a long time GNU / Linux user, I've been quite dissatisfied for the fact that in latest Debian and Ubuntu Linux, the default Key combination to Kill X (CTRL + ALT + BACKSPACE) is no longer working.

Though nowdays Xorg (XServer) is pretty stable it still happens from time to time for some application to overload the PC badly and make Gnome or KDE environment little or no responsive at all and here comes the goody CTRL + ALT + BACKSPACE it is pretty much  like  (CTRL + ALT + DEL) did restarted the computer in DOS and earlier Windows OS-es once the environment became unusable with the only difference that just Xorg server is restarted and the other using programs that are in background work just like they used to. 

CTRL + ALT + Backspace is a great thing to use especially if you're running some homebrew server and you use it both as a Server with some few little websites and as a Desktop environment to browse the net and do basic stuff.

So here comes the question how to make the CTRL + ALT + BACKSPACE keyboard combination be killing Xserver like in the good old days?

The easiest way to do it interactively in ncurses interface is by  running:

 

root@noah:~# dpkg-reconfigure keyboard-configuration

 

If somehow on the machine you don't have dpkg-reconfigure or you prefer to do set CTRL + ALT + BACKSPACE Kill Switch manually edit /etc/default/keyboard 

inside change value of

 

XKBOPTIONS="terminate:ctrl_alt_bksp" 

 

like shown below file:

root@noah:/home/hipo# cat  /etc/default/keyboard

# KEYBOARD CONFIGURATION FILE

# Consult the keyboard(5) manual page.

XKBMODEL="pc105"
XKBLAYOUT="us"
XKBVARIANT=""
XKBOPTIONS="terminate:ctrl_alt_bksp"

BACKSPACE="guess"

The configuration should be working across Debian 7, 8, 9 as well as Ubuntu 12 ..14 .. 16 and hopefully in future releases too, just as many other Linux distributions like Mint etc. the Xserver Kill Switch setting should be located in same file.

Finally if even after that change the Control Alt BackSpace Kill Switch sequence refuses to work in GNOME Desktop environment, it might be due to a local setting typical for GNOME and this should be fixed via the good known gnome-tweak-tool

So GNOME users should run it from command line and check the setting there, e.g.:

 

$ gnome-tweak-tool


You should check:


 

Typing -> Kill Sequence to Kill the X Server

 


it should look like shown in below screenshot:

how-to-set-X-server-kill-switch-in-GNOME-gnak-tool-screenshot-debian-stretch

 

 

 

 

ZenMap Nmap multi platform Graphical frontend for checking port security

Saturday, June 15th, 2013

graphic program to scan remote network server port security on GNU Linux and Windows ZenMap

Recently I wrote little article with some examples for scanning server port security with Nmap. I forgot to mention in the article that there is also Nmap frontend GUI program called ZenMap. ZenMap port is available for both Windows and Linux. In Debian, Ubuntu, Mint and other debian derivative distributions ZenMap is available from standard package repositories;

 noah:~# apt-cache show zenmap|grep -i description -A 3

Description-en: The Network Mapper Front End
 Zenmap is an Nmap frontend. It is meant to be useful for advanced users
 and to make Nmap easy to use by beginners. It was originally derived
 from Umit, an Nmap GUI created as part of the Google Summer of Code.
Description-md5: 4e4e4c6aeaa4441484054473e97b7168
Tag: implemented-in::python, interface::x11, network::scanner, role::program,
 uitoolkit::gtk, use::scanning, x11::application
Section: net

To install  ZenMap on Debian / Ubuntu Linux:

noah:~# apt-get install --yes zenmap
...

In Fedora, CentOS and other RPM based Linux-es to install ZenMap run:

noah:~# yum -y install nmap-frontend nmap
...

To use Nmap's Frontend full functionality, you have to run it as (root) superuser:

hipo@noah:~$ sudo su
[sudo] password for hipo:
noah:~# zenmap

Zenmap saves, a lot of time as there is no need to  remember Nmap's arguments or run few Nmap scans until you get essential information for remote scanned machine.
It automatically gives details on Remote server running services (fingerprint)

Zenmap remote server security services scan with services software version

Very useful report it makes as well is network (and host) topology diagram,

network scanner remote host Linux Windows toplogy guess ZenMap screenshot

ZenMap is just Nmap frontend and under the GUI it does use Nmap with various arguments to do produce scan results. In Nmap Output tab, you can see a lot of verbose info.

Zenmap Linux Windows GUI port scanne nmap output tab screen Debian / Ubuntu Linux

Happy scanning 🙂

HasciiCAM supposed to stream ASCII video over the network on GNU / Linux

Tuesday, May 22nd, 2012

Richard M. Stallman (RMS) Face portrait rendered in ASCII art from a video with hasciicam
To continue with my lately ASCII centered articles I found hasciicam
hasciicam is a program to stream ASCII video over the network on Linux and probably can be easily made working on FreeBSDtoo.

The project concept is interesting in a matter of fun (play) point of view, however not too usable as we all know ASCII character looking faces doesn't look too pretty.

Below is the Debian (Squeeze) package description:

noah:~# apt-cache show hasciicam|grep -i description -A 7
Description: (h)ascii for the masses: live video as text
Hasciicam makes it possible to have live ASCII video on the web. It
captures video from a tv card and renders it into ascii, formatting the
output into an html page with a refresh tag or in a live ASCII window or
in a simple text file as well, giving the possibility to anybody that has a
bttv card, a Linux box and a cheap modem line to show a live ASCII video
feed that can be browsable without any need for plugin, java etc.
Homepage: http://ascii.dyne.org/

On hasciicam Project webpage is it is stated as a hardware you need to have:
 

"As hardware you need to have a webcam or a videocard supported by "video 4 linux", most of the gear you can buy around should work well."

To install and test it I run:

noah:~# apt-get --yes install hasciicam

Though it is stated on the project website supposed to work display video fine with most 'linux ready' webcams, it didn't with this very standard one.

Here is the exact WebCamera model as identified to the kernel:

noah:~# dmesg|grep -i camera
[ 1.433661] usb 2-2: Product: USB2.0 Camera
[ 10.107840] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1e4e:0102)
[ 10.110660] input: USB2.0 Camera as /devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2:1.0/input/input11

By the way, I use the very same CAM daily on for Skype video calls as well as the Camera is working with no problems to save video or pictures inside Cheese

Here is the exact WebCamera model as identified to the kernel:

noah:~# dmesg|grep -i camera
[ 1.433661] usb 2-2: Product: USB2.0 Camera
[ 10.107840] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1e4e:0102)
[ 10.110660] input: USB2.0 Camera as /devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2:1.0/input/input11

The just installed deb has one binary file only /usr/bin/hasciicam. To test it with the camera I issued:

noah:~# hasciicam -d /dev/video0
HasciiCam 1.0 - (h)ascii 4 the masses! - http://ascii.dyne.org
(c)2000-2006 Denis Roio < jaromil @ dyne.org >
watch out for the (h)ASCII ROOTS

Device detected is /dev/video0
USB2.0 Camera
1 channels detected
max size w[640] h[480] - min size w[48] h[32]
Video capabilities:
VID_TYPE_CAPTURE can capture to memory
!! error in ioctl VIDIOCGMBUF: : Invalid argument

Unfortunately as you see from the output, it failed to detect the web camera model.
The exact camera besides its kernel detection naminf is a cheap external USB 2.0 (fake brand / nonanem) "universal" Web PC Camera (SUPER .3mega pixel)

For those who have a further interest in building and installing hasciicam on other Linux platforms than Debian and Ubuntu or whoever wants to look in the code check check Project webpage is. For those who are less of programmers (like me) the project is written in C programming language and uses aa-lib in order to render the video to ASCII.

On the site you will notice two totally schizophrenic looking pictures of presumably the project head developer …

hasciiart video streamed ASCII screenshot of some crazy looking guy smoking marijuanna or smth

As I read in man hasciicam manual page it's said to be able to generate ascii plain text and html files as well as directly to write the output to console, which later probably can be streamed via the network.
Pitily as it didn't detect my camera I couldn't make some testing of its network capabilities.

A Streaming of ASCII couuld be done through pushing the .html output to a webserver and setting a php or javascript to loop through and refresh the browser over the uploaded files every sec or so.

Also I assume the ASCII video output saved in plain console could be streamed via netcat or some tiny scripted perl or bash script and directly observed via a telnet or ssh connection.
One playful way I can think of checking a stored video without the use of FTP is to login via ssh and do:

$ ssh someuser@somehost
$ watch -n 1 "cat video-ascii.html"

🙂

Well something disturbing about hasciicam from a (purely Christian point of view) is it was developed by some kind of non profit organization called RastaSoft on the project website, some of its authors has written JAH BLESS.

As I didn't succeeded seeing it working, I'll be interested to hear if someone who red this article and give it a try can report the web camera model used.

AEWAN – a nice advanced GNU / Linux console ASCII art text editor

Saturday, May 19th, 2012

I'm a guy fascinated by ASCII art, since the very early days I saw a piece of this awesome digital art.

As time passed and computers went to be used mostly  graphics resolution, ASCII art loose its huge popularity from the early DOS and BBS (internet primordial days).

However, this kind  of art is still higly valued by true computer geeks.
In that manner of thoughts, lately I'm researching widely on ASCII art tools and ASCII art open source tools available for Linux.
Last time I check what is available for 'ASCII job' was before 5 years time. Recently I decided to review once again and see if there are new software for doing ascii manipulations on Linux and this is how this article got born.

My attention was caught by aewan (ASCII-art Editor Without A Name), while searching for ASCII keyword description packages with:

apt-cache search ascii

Aewan project official website is on sourceforge check it out here

Here is the complete description of the Debian package:

hipo@noah:~$ apt-cache show aewan|grep -i description -A 5
Description: ASCII-art Editor Without A Name
aewan is an ASCII art editor with support for multiple layers that can be
edited individually, colors, rectangular copy and paste, and intelligent
horizontal and vertical flipping (converts '\' to '/', etc). It produces
both stand-alone art files and an easy-to-parse format for integration
into your terminal applications.

I installed it to give it a try:

noah:~# apt-get --yes install aewan
Selecting previously deselected package aewan.
(Reading database ... 388522 files and directories currently installed.)
Unpacking aewan (from .../aewan_1.0.01-3_amd64.deb) ...
Processing triggers for man-db ...
Setting up aewan (1.0.01-3) ...

aewan package provides three executable binaries:

noah:~# dpkg -L aewan|grep -i /bin/ /usr/bin/aecat
/usr/bin/aewan
/usr/bin/aemakeflic

1. aewan binary is the ascii-art editor itself

2. aecat is utility to display an aewan documents (aewan format saved files)3. aemakeflictool to produce an animation from an aewan document

Next I ran it in plain console tty  to check how it is like:

hipo@noah:~$ aewan

Below are screenshots to give you an idea how powerful aewan ASCII art editor is:

AEWAN ASCII art editor entry information screen Debian GNU / Linux shot

Aewan immediate entry screen after start up

Aewan ASCII art editor Linux showing the major functionality of aewan on Debian GNU / Linux Squeeze

Aewan ASCII art editor – all of the supported tool functions

As you can see from the shot the editor is very feature rich. I was stunned to find out it even supports layers (in ASCII!!) (w0w!). 
It even has a Layers Manager (like GIMP) 🙂

To create my first ASCII art I used the:

New

menu.

This however didn't immediately show the prompt, where I can type  the ascii characters to draw my picture. In order to be able to draw inside the editor, its necessary to open at least one layer, through using the menu:

Add Layer (defaults)

then the interactive ASCII art editor appeared.

While an ASCII art is created with the editor you can select the color of the input characters by using Drawing Color menu seen in the above screenshot.

aewan drawing color choose color Linux shot

I've played few minutes and created a sample ascii art, just to test the color and editor "look & feel", my conclusions are the editor chars drawing is awesome.

Aewan ascii art produced on my Debian GNU / Linux host

All the commands available via menus are also accessible via a shortcut key combinations:

Aewan Linux Ascii art editor quick key shortcut commands

aewan controls are just great and definitely over-shadows every other text editor I used to draw an ASCII art so far.
Once saved the ASCII art, are by default saved in a plain gzipped ascii text. You can therefore simply zcat the the saves;
Don't expect zcat to show you the ascii as they're displayed in aewan, zcat-ing it will instead  display just the stored meta data; the meta data is interpreted and displayed properly only with aecat command.

aewan aecat displaying properly previously saved ascii art picture

I've checked online for rpm builds too and such are available, so installing on Fedora, CentOS, SuSE etc. is up to downloading the right distro / hardware architecture rpm package and running:

# rpm -ivh aewan*.rpm

On the official website, there are also instructions to compile from source, Slackware users and users of other distros which doesn't have a package build should compile manually with the usual:

$ tar -zxf aewan-1.0.01.tar.gz
$ cd aewan-1.0.01
$ ./configure
$ make
$ su -c "make install"

For those inrested to make animations with aemakeflic you need to first save a multiple layers of pictures. The idea of creating ASCII art video is pretty much like the old school way to make animation "draw every scene" and movie it. Once all different scene layers of the ASCII art animation are prepared one could use  aemakeflic to export all the ASCII layers as common video.

aemakeflic has the ability to export the ASCII animation in a runnable shell script to display the animation. The other way aemakeflic can be used is to produce a picture in kind of text format showing the video whether seen with  less cmd.
Making ASCII animation takes a lot of time and effort. Since i'm too lazy and I lack the time I haven't tested this functionality. Anyways I've seen some ascii videos on telnet  to remote hosts (some past time); therefore I guess they were made using aewan and later animated with aemakeflic.

I will close this post with a nice colorful ASCII art, made with aewan (picture is taken from the project page):

Aewan Flipping Selection Screenshot
 

Viewing JPEG,GIF and PNG in ASCII with cacaview on GNU / Linux – Review on caca-utils text mode graphics utilities

Thursday, May 17th, 2012

Stitch 80x45 libcaca mascot cacaview viewing JPG, PNG, GIF images as ASCII on Linux libcaca

Probably, many don't know that it is possible to view normal graphical pictures (JPG, PNG, GIF, BMP) etc. in plain console tty.

Being able to view pictures in ASCII is something really nice especially for console geeks like me.
The images produced sometimes are a bit unreadable, if compared to the original graphics, but anyways most of the pictures looks pretty decent 🙂

Viewing in console / terminal images on GNU / Linux is possible thanks to a library called libcaca, caca labs libcaca project official website here.
Below is a shot description of libcaca:
hipo@noah:~$ apt-cache show libcaca0|grep 'Description' -A 4
Description: colour ASCII art library
libcaca is the Colour AsCii Art library. It provides high level functions
for colour text drawing, simple primitives for line, polygon and ellipse
drawing, as well as powerful image to text conversion routines.

In Debian, Ubuntu and other deb Linux distros viewing GUI images with no need for Xserver or any kind of window manager in plain ASCII is possible with cacaview.

cacaview is part of a package called caca-utils. caca-utils is providing few other great utilities for ASCII freaks 🙂 along with cacaview console ascii viewer prog.
The package> is available for Debian distributins since many years, so even on a very old Debians like Debian – (Potato, Woody, Sarge) the package is available in default free package repositories ready to install via apt

To install apt-get it as usual:

noah:~# apt-get --yes install caca-utils

Here is a list of the binaries the package provides:

hipo@noah:~$ dpkg -L caca-utils|grep -i /usr/bin/
/usr/bin/cacaserver
/usr/bin/cacaplay
/usr/bin/cacafire
/usr/bin/cacademo
/usr/bin/cacaview
/usr/bin/img2txt

1. cacaserver a tiny program allowing network streaming of applications written in caca

Belkow is a chop, from man cacaserver
 

cacaserver reads libcaca animation files in its standard input and
serves them as ANSI art on network port 51914. These animations can be
created by any libcaca program by setting the CACA_DRIVER environment
variable to raw and piping the program's standard output to cacaserver.

Clients can then connect to port 51914 using telnet or netcat to see
the output.

The example section of the manual points 1 example use of cacaserver to stream the console output from cacademo.
cacademo binary is a short presentation ASCII DEMO in the spirit of the old school assembly demos (demoscene) .
To run it to bind on port 51914 one has to type in bash shell:
hipo@noah:~$ CACA_DRIVER=raw cacademo | cacaserver
initialised network, listening on port 51914

Then to check out how the demo looks, open telnet connection to the cacaserver host; In my case the cacaserver is binded and streamed over IP 192.168.0.2:

hipo@debian:~$ telnet 192.168.0.2 51914

Immediately you got the demo shining; Below are two screenshots of the demo played after succesful telnet connection:

Cacaserver - caca for the network screenshot Matrix cacademo

cacademo running over telnet network connection – Matrix

cacaserver running on Debian GNU / Linux drug addict like spots streamed via telnet

Blur spots cacademo shot of cacademo streamed via network

You see the demo looks quite awesome 🙂

2. Running cacafire to stream over network

Another possible example use of cacaserver is in conjunction with cacafire libcaca test application:

noah:~# CACA_DRIVER=raw cacafire | cacaserver
initialised network, listening on port 51914
cacafire is a short application written to render ASCII via libcaca and is just displaying a screen with ASCII (moving) burning fire.
It is quite spectacular if you, ask an unexpecting friend to connect to your host to 51914 🙂

Cacafire Screenshot Debian GNU / Linux cacaserver streaming ASCII demo via network port 51914

Besides that bored sys admins, could run cacafire in console to hypnotize themselves watching dumb the burning fire screen for few hoursor just use it as a screensaver 😉

3. cacaview a program to display a graphic images in console using ASCII art

cacaview takes just one argument – the picture to be displayed.

Below is a screenshot of cacaview ran from my gnome-terminal displaying a ASCII text version of the MySQL server logo

hipo@noah:~$ cd /disk/pictures
hipo@noah:/disk/pictures$ cacaview mysql_logo.png

 

cacaview displaying MySQL database logo in ASCII using caca for X

Whether cacaview is invoked in GUI, the libcaca X support is used, so the text image is visualized in new window with graphics, if however it is invoked in plain let's say tty1 libcaca displays the graphics pictures drawing it with only text characters.

Here is also a screenshot, I've made while viewing a GIF website logo in ASCII in plain tty console:

hipo@noah:~$ cacaview /disk/pictures/logo.gif

cacaview plain tty console screenshot of a website logo graphics pictures 17-05-2012

The logo is in cyrillic, so for latin speaking people some of the characters in the two words seen will be unreadable 🙂

cacaview even supports viewing, the next and previous picture in line, like in any modern graphics image viewer program.
To view a bunch of graphic pictures in ASCII with cacaview pass it *.*:

hipo@noah:~$ cacaview /disk/pictures/*.*

For simplicity the common unix * is also supported, so I find it quicker to do:

hipo@noah:~$ cacaview /disk/pictures/*

Showing pictures forward and backward (Previous / Next) picture is done with n and p kbd keys, whether;
n - next;
p - previous

cacaview doesn't crash or stop but skip unknown file formats – if for instance encounters filenames which are not images; lets say you have *.rar archive files along with other pictures.

The complete list of keys cacaview supports are:
br />

KEYS
? show the help screen

n, p switch to next image, previous image

Left, Right, Up, Down or h, l, k, j
scroll the image around

+, – zoom in and out

z reset the zoom level to normal

f switch fullscreen mode (hide/show menu and status bars)

d toggle the dithering mode (no dithering, 4×4 ordered dithering, 8×8 ordered dithering and random dithering)

q exit the program

4. Converting graphics images to ASCII art like (plain text pictures)

The tool that does "the trick" is img2txt. img2txt has a bit more options while compared to the rest of the aforementioned tools.The following list of arguments are recognized:

  • the size (font, height)
  • brightness
  • contrast
  • gamma and dither
  • format type of out the output pic

Anyways I found that the basic just in / out arguments passed are enough to produce pretty good results:

hipo@noah:~$ img2txt hipo_avatar.gif >hipo_avatar_pic.txt

The original hipo_avatar.gif file looks like so:

hipo avatar gif picture before img2txt convertion to text

After above img2txt command is run and hipo_avatar_pic.txt to see the colorful output ASCII art img2txt produces, cat it:

hipo@noah:~$ cat hipo_avatar_pic.txt

The image result if screenshot looks quite beautiful and even, can be considered or used as an ART effect image (filter) 🙂

Console Screenshot hipo avatar pic ASCII img2txt output picture

The picture colors are plain ANSI color, so in order to display properly the picture with colors on another computers or Operating System you will need at least basic support for ANSI colors.

Plenty of output file formats are supported by img2txt

Here is the complete list of supported output formats:
 

ansi : coloured ANSI
caca : internal libcaca format
utf8 : UTF8 with CR
utf8 : UTF8 with CRLF (MS Windows)
html : HTML with CSS and DIV support
html3 : Pure HTML3 with tables
irc : IRC with ctrl-k codes
bbfr : BBCode (French)
ps : Postscript
svg : Scalable Vector Graphics
tga : Targa Image

libcaca is available for FreeBSD too, but the caca-utils is not available as a port yet, though probably the deb or rpm packages can easily be ported to BSD.

Well that's all, Enjoy.

Text Monitoring of connection server (traffic RX / TX) business in ASCII graphs with speedometer / Easy Monitor network traffic performance

Friday, May 4th, 2012

While reading some posts online related to MS-Windows TcpViewnetwork traffic analyzing tool. I've came across very nice tool for tracking connection speed for Linux (Speedometer). If I have to compare it, speedometer is somehow similar to nethogs and iftop bandwidth network measuring utilities .

What differentiates speedometer from iftop / nethogs / iptraf is it is more suitable for visualizing a network file or data transfers.
The graphs speedometer draws are way easier to understand, than iftop graphs.

Even complete newbies can understand it with no need for extraordinary knowledge in networking. This makes Speedometer, a top tool to visually see the amount of traffic flowing through server network interface (eth0) … (eth1) etc.

What speedometer shows is similar to the Midnight Commander's (mc) file transfer status bar, except the statistics are not only for a certain file transfer but can show overall statistics over server passing network traffic amount (though according to its manual it can be used to also track individual file transfers).

The simplicity for basic use makes speedometer nice tool to track for network congestion issues on Linux. Therefore it is a  must have outfit for every server admin. Below you see a screenshot of my terminal running speedometer on a remote server.

Speedometer ascii traffic track server network business screenshot in byobu screen like virtual terminal emulator

1. Installing speedometer on Debian / Ubuntu and Debian derivatives

For Debian and Ubuntu server administrators speedometer is already packaged as a deb so its installation is as simple as:

debian:~# apt-get --yes install speedometer
....

2. Installing speedometer from source for other Linux distributions CentOS, Fedora, SuSE etc.

Speedometer is written in python programming language, so in order to install and use on other OS Linux platforms, it is necessery to have installed (preferably) an up2date python programming language interpreter (python ver. 2.6 or higher)..
Besides that it is necessary to have installed the urwid -( console user interface library for Python) available for download via excess.org/urwid/

 

Hence to install speedometer on RedHat based Linux distributions one has to follow these steps:

a) Download & Install python urwid library

[root@centos ~]# cd /usr/local/src
[root@centos src]# wget -q http://excess.org/urwid/urwid-1.0.1.tar.gz
[root@centos src]# tar -zxvvf urwid-1.0.1.tar.gz
....
[root@centos src]# cd urwid-1.0.1
[root@centos urwid-1.0.1]# python setup.py install
running install
running build
running build_py
creating build
creating build/lib.linux-i686-2.4
creating build/lib.linux-i686-2.4/urwid
copying urwid/tests.py -> build/lib.linux-i686-2.4/urwid
copying urwid/command_map.py -> build/lib.linux-i686-2.4/urwid
copying urwid/graphics.py -> build/lib.linux-i686-2.4/urwid
copying urwid/vterm_test.py -> build/lib.linux-i686-2.4/urwid
copying urwid/curses_display.py -> build/lib.linux-i686-2.4/urwid
copying urwid/display_common.py -> build/lib.linux-i686-2.4/urwid
....

b) Download and install python-setuptools

python-setuptools is one other requirement of speedometer, happily on CentOS and Fedora the rpm package is already there and installable with yum:

[root@centos ~]# yum -y install python-setuptools
....

c) Download and install Speedometer

[root@centos urwid-1.0.1]# cd /usr/local/src/
[root@centos src]# wget -q http://excess.org/speedometer/speedometer-2.8.tar.gz
[root@centos src]# tar -zxvvf speedometer-2.8.tar.gz
.....
[root@centos src]# cd speedometer-2.8
[root@centos speedometer-2.8]# python setup.py install
Traceback (most recent call last):
File "setup.py", line 26, in ?
import speedometer
File "/usr/local/src/speedometer-2.8/speedometer.py", line 112
n = n * granularity + (granularity if r else 0)
^

While running the CentOS 5.6 installation of speedometer-2.8, I hit the
"n = n * granularity + (granularity if r else 0)
error.

After consultation with some people in #python (irc.freenode.net), I've figured out this error is caused due the outdated version of python interpreter installed by default on CentOS Linux 5.6. On CentOS 5.6 the python version is:

[root@centos ~]# python -V
Python 2.4.3

As I priorly said speedometer 2.8's minimum requirement for a python to be at v. 2.6. Happily there is quick way to update python 2.4 to python 2.6 on CentOS 5.6, as there is an RPM repository maintained by Chris Lea which contains RPM binary of python 2.6.

To update python 2.4 to python 2.6:

[root@centos speedometer-2.8]# rpm -Uvh http://yum.chrislea.com/centos/5/i386/chl-release-5-3.noarch.rpm[root@centos speedometer-2.8]# rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CHL[root@centos speedometer-2.8]# yum install python26

Now the newly installed python 2.6 is executable under the binary name python26, hence to install speedometer:

[root@centos speedometer-2.8]# python26 setup.py install
[root@centos speedometer-2.8]# chown root:root /usr/local/bin/speedometer
[root@centos speedometer-2.8]# chmod +x /usr/local/bin/speedometer

[root@centos speedometer-2.8]# python26 speedometer -i 1 -tx eth0

The -i will instruct speedometer to refresh the screen graphs once a second.

3. Using speedometer to keep an eye on send / received traffic network congestion

To observe, the amount of only sent traffic via a network interface eth0 with speedometer use:

debian:~# speedometer -tx eth0

To only keep an eye on received traffic through eth0 use:

debian:~# speedometer -rx eth0

To watch over both TX and RX (Transmitted and Received) network traffic:

debian:~# speedometer -tx eth0 -rx eth0

If you want to watch in separate windows TX and RX traffic while  running speedometer you can run in separate xterm windows speedometer -tx eth0 and speedometer -rx eth0, like in below screenshot:

Monitor Received and Transmitted server Network traffic in two separate xterm windows with speedometer ascii graphs

4. Using speedometer to test network maximum possible transfer speed between server (host A) and server (host B)

The speedometer manual suggests few examples one of which is:

How fast is this LAN?

host-a$ cat /dev/zero | nc -l -p 12345
host-b$ nc host-a 12345 > /dev/null
host-b$ speedometer -rx eth0

When I red this example in speedometer's manual, it wasn't completely clear to me what the author really meant, but a bit after when I thought over the example I got his point.

The idea behind this example is that a constant stream of zeros taken from /dev/zero will be streamed over via a pipe (|) to nc which will bind a port number 12345, anyone connecting from another host machine, lets say a server with host host-b to port 12345 on machine host-a will start receiving the /dev/zero streamed content.

Then to finally measure the streamed traffic between host-a and host-b machines a speedometer is started to visualize the received traffic on network interface eth0, thus measuring the amount of traffic flowing from host-a to host-b

I give a try to the exmpls, using for 2 test nodes my home Desktop PC, Linux running  arcane version of Ubuntu and my Debian Linux notebook.

First on the Ubuntu PC I issued
 

hipo@hip0-desktop:~$ cat /dev/zero | nc -l -p 12345
 

Note that I have previously had installed the netcat, as nc is not installed by default on Ubuntu and Debian. If you, don't have nc installed yet, install it with:

apt-get –yes install netcat

"cat /dev/zero | nc -l -p 12345" will not produce any output, but will display just a blank line.

Then on my notebook I ran the second command example, given in the speedometer manual:
 

hipo@noah:~$ nc 192.168.0.2 12345 > /dev/null

Here the 192.168.0.2 is actually the local network IP address of my Desktop PC. My Desktop PC is connected via a normal 100Mbit switch to my routing machine and receives its internet via  NAT. The second test machine (my laptop), gets its internet through a WI-FI connection received by a Wireless Router connected via a UTP cable to the same switch to which my Desktop PC is connected.

Finally to test / get my network maximum thoroughput I had to use:

hipo@noah:~$ speedometer -rx wlan0

Here, I  monitor my wlan0 interface, as this is my (laptop) wireless card interface over which I have connectivity to my local network and via which through the the WI-FI router I get connected to the internet.

Below is a snapshot captured showing approximately what is the max network thoroughput from:

Desktop PC -> to my Thinkpad R61 laptop

Using Speedometer to test network thorougput between two network server hosts screenshot Debian Squeeze Linux

As you can see in the shot approximately the maximum network thoroughput is in between:
2.55MB/s min and 2.59MB/S max, the speed is quite low for a 100 MBit local network, but this is normal as most laptop wireless adapters hardly transfer traffic in more than 10 to 20 MBits per sec.

If the same nework thoroughput test is conducted between two machines both connected to a same 100 M/bit switch, the traffic should be at least a 8 MB/sec.

There is something, else to take in consideration that probably makes the provided example network thoroughput measuring a bit inaccurate. The fact that the /dev/zero content is stremed over is slowing down the zeroes sent over network because of the  pipe ( | ) use slows down the stream.

5. Using speedometer to visualize maximum writting speed to a local hard drive on Linux

In the speedometer manual, I've noticed another interesting application of this nifty tool.

speedometer can be used to track and visualize the maximum writing speed a hard disk drive or hard drive partition can support on Linux OS:

A copy paster from the manual text is as follows:

How fast can I write data to my filesystem? (with at least 1GB free)
dd bs=1000000 count=1000 if=/dev/zero of=bigfile &
speedometer bigfile

However, when I tried copy/pasting the example in terminal, to test the maximum writing speed to an external USB hard drive, only dd command was started and speedometer failed to initialize and display graphs of the file creation speed.

I've found a little "hack" that makes the man example work by adding a 3 secs sleep like so:

debian:/media/Expansion Drive# dd bs=1000000 count=1000 if=/dev/zero of=bigfile & sleep 3; speedometer bigfile

Here is a screenshot of the bigfile created by dd and tracked "in real time" by speedometer:

How fast is writting data to local USB expandable hard disk Debian Linux speedometer screenshot

Actually the returned results from this external USB drive are, quite high, the possible reason for that is it is connected to my laptop over an USB protocol verion 3.

6. Using Speedometer to keep an eye on file download in progress

This application of speedometer is mostly useless especially on Linux where it is used as a Desktop.

However in some occasions if files are transferred over ssh or in non interactive FTP / Samba file transfers between Linux servers it can come handy.

To visualize the download and writing speed of lets say FTP transferred .AVI movie (during the actual file transfer) on the download host issue:

# speedometer Download-Folder/What-goes-around-comes-around.avi

7. Estimating approximate time for file transfer

There is another section in the speedometer manual pointing of the program use to calculate the time remaining for a file transfer.

The (man speedometer) provided example text is:

How long it will take for my 38MB transfer to finish?
speedometer favorite_episode.rm $((38*1024*1024))

At first glimpse it hard to understand (like the other manual example). A bit of reasoning and I comprehend what the man author meant by the obscure calculation:

$((38*1024*1024))

This is a formula used in which 38 has to be substituted with the exact file size amount of the transferred file. The author manual used a 38MB file so this is why he put $((38* … in the formula.

I give it a try – (just for the sake to see how it works) with a file with a size of 2500MB, in below two screenshot pictures I show my preparation to copy the file and the actual copying / "real time" transfer tracking with speedometer's status percentage completion bar.

xterm terminal copy file and estimate file copying operation speed on linux with speedometer preparation

Two xterm terminals one is copying a file the other one uses speedometer to estimate the time remaining to complete the file transfer from expansion USB hard drive to my laptop harddrive