Linux and Unix tips

Used size when creatng backup disk with EXT4

2014-04-27T11:05:00.000-07:00

You might want to backup your data ! So you use the EXT4 partition format for your new disk but after formatting you realize that many free doesn't meet the total size you expect !

1To default ext4 format will take 5% of disk : 20 Go. It's a lot !

If you just use your disk as a backup disk, you don't need EXT4 to take so much free space (5% by default).

Will take 5% of free space:

$> sudo tune2fs -m 5 /dev/sdb1

Will take 0% of free space:

$> sudo tune2fs -m 0 /dev/sdb1

Source : http://odzangba.wordpress.com/2010/02/20/how-to-free-reserved-space-on-ext4-partitions/

Set up Regional Settings with command line

2014-01-05T06:40:00.001-08:00

Set up Regional Settings with command line

Linux Mint user interface is not clear about setting the exact information you need for your local system languages for Time, Numeric, Measurement values.

Just edit /var/lib/locales/supported.d/local

Should look like :

fr_FR.UTF-8 UTF-8
en_US.UTF-8 UTF-8

Then run :
$> sudo dpkg-reconfigure locales

Finally edit /etc/default/locale
and change the locale you need for every line you need.

Source: http://forums.linuxmint.com/viewtopic.php?f=47&t=76645

Change timezone from the command line

2013-08-04T08:28:00.002-07:00

With the new Linux Mint 15, there is no more the graphical option for changing his local timezone... Which is a bit annoying. This was reported in the main blog thread.
So it's quite simple to change it from the command line :

$> timedatectl list-timezones

Will list all the timezones you need. So try

$> timedatectl list-timezones | grep -i paris

To know about the timezone in Paris.
Then set the corresponding timezone for the system

$> timedatectl set-timezone `timedatectl list-timezones | grep -i paris`

Voila !

Fix PhotoStation on your synology

2013-01-02T12:33:00.000-08:00

If you have a "500 Server Error" while browsing the PhotoStation application on you Synology, this is because there is a problem with the configuration of your Synology (It has never been fixed by Synology).
Well I will skip all the details of how to find this out (enable logs on the apache-user service and dig the problem with the logs).

First, login as root on your Synology
```
$> ssh root@your-synology
```
Then edit the /usr/syno/etc/php/user-setting.ini file
```
$> vi /usr/syno/etc/php/user-setting.ini
```
And add this line (via the "i" key) :
```
extension_dir = "/lib/php/extensions/"
```

More information : http://forum.synology.com/enu/viewtopic.php?f=17&t=50336

PS : the PhotoStation PHP is very old and doesn't look secured at all...

Suspend your linux with the command line

2013-01-01T05:54:00.000-08:00

After searching for quite a long time how to efficiently suspend your linux with a command and not using the GUI, the best way to do it is to use "pm-suspend-hybrid" :

$> sudo pm-suspend-hybrid

Source : http://www.cyberciti.biz/faq/linux-command-to-suspend-hibernate-laptop-netbook-pc/

CPU high load on Fedora 17 from evince-thumbnailer

2012-09-08T02:37:00.001-07:00

Well, as I say on my previous email, my laptop suddenly started to overheat with no reason. I decided to scale the CPU frequency down, with some success to reduce the temperature. But the problem wasn't there !

I should have done this before, but anyway:

$> top

Here is the result :

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
5120 max       20   0  140m 3004 2904 R 99.4  0.1 479:14.69 evince-thumbnailer

So here is the guilty party : more than 8h that the CPU is running at his top !! Doing a bit of digging :


$ ps aux | grep evince-thumbnailer

evince-thumbnailer -s 128 file:///XXXX.xps /tmp/.XXX

That's it ! There is a major bug with parsing XPS files. Here is the bug report for using 100% CPU load with evince-thumbnailer.

Solution : well this is very dirty but I guess it's working.

sudo su
rm /bin/evince-thumbnailer
echo "exit 0" > /bin/evince-thumbnailer
chmod 755 /bin/evince-thumbnailer

Should make no more infinite loop now :)

Linux CPU downscaling frequency

2012-09-07T07:33:00.002-07:00

As my laptop is overheating, even if there is no heavy task running on my Linux, I tried to downscale the CPU frequency to produce less heat and hopefully use less power so have better battery life !

As I'm using Fedora 17, I couldn't find an easy GUI tool to change it nicely like I could do before from the Gnome toolbar. Well, my searches headed me to the official documentation.

1. First, grab the weakest frequency your CPU could run :


cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies

will output something like this :


1601000 1600000 1500000 1400000 1300000 1200000 1100000 1000000 900000 800000

In my case it's 800000.

2. Then update the CPU max frequency setting

As root, now change the value on the /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq file to this value

echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

3. Apply to all your CPUs (or cores)


echo 800000 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq


echo 800000 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq


echo 800000 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq

As a result, my computer is getting MUCH cooler after this update... I'll tell you later if I see a lot of performance decrease. In this case I will temporary update the value to the max frequency to all these files.

PS : another way to achieve this is to change the "governor" policy for the frequency. Just use the "powersave" policy instead of the default "ondemand" one with :


echo "powersave" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Benchmarking Linux

2012-08-08T15:48:00.000-07:00

Some people like to see what's the machine's like right after a fresh install... and Linux does not come with easy out-of-the-box benchmarking tools.

This is why, after digging and been flooded with a lot of tools, there is one which was more appealing than the others because it's easy to install, run, and see the results. It's name is Phoronix.

Install with

sudo apt-get install phoronix-test-suite

Run test with

phoronix-test-suite interactive

The follow the assistant and usually run the #3 "Complex System Test" test and let the program do the job.

At the end, the results are published into a web page available in your home directory :

firefox .phoronix-test-suite/test-results/desktop/index.html

Here is a copy of my benchmark result.

Sparkleshare no icon on XFCE

2012-08-06T07:11:00.000-07:00

If you want to use Sparkleshare (Dropbox equivalent but on your own server / private server) with the XFCE UI, the default package on Linux Mint 13 will fail because the icon will not popup in the system tray.

The solution is to build the latest version (Sparkleshare 0.9.0) :

1. Make sure you uninstall the default package and stopped it

sparkleshare stop
sudo apt-get remove sparkleshare
# Remove files & configuration files
rm -Rf ~/SparkleShare
rm -Rf ~/.config/sparkleshare

2. Install the dependancies for building Sparkleshare

sudo apt-get install mono-runtime mono-devel monodevelop mono-mcs mono-gmcs libwebkit-cil-dev libnotify-cil-dev

3. Download Sparkeshare code source

cd ~/Downloads
wget https://github.com/downloads/hbons/SparkleShare/sparkleshare-linux-0.9.0.tar.gz
tar wxzf sparkleshare-linux-0.9.0.tar.gz
cd sparkleshare-linux-0.9.0
# --prefix=/usr is important
./configure --prefix=/usr
make
sudo make install

4. Run Sparkleshare

sparkleshare start

You should see the icon in the systray.

Source : https://github.com/hbons/SparkleShare/issues/803

Sharing my Linux distro experience

2012-08-05T14:01:00.000-07:00

Been a big fan of Linux since this OS is the best option for me (well since there is no pain in the ass installation and configuration even for advanced users).

Cinnamon

I switch recently to Linux Mint 13. This Linux is just "butter" compared to the others distros I used before : so neat, so fast and so easy to install, no big bug, and a very fast & clever UI (Cinnamon).
Here is some of my recent experience shared.

XFCE

Update: as many geeks gave me a good review about XFCE, I also tried the XFCE with Linux.
Could be a good combination to have a very light UI, plus a good launcher like Synapse.

After a good start, I wanted to connect to a Wifi network... Well, believe me or not, by default you can choose the network but the password popup never comes !! Even if you try to setup the connection by hand from the network manager, you cannot set any properties (rights problem ?). Such a bad experience in front of my client (!!!!!).

I met a lot of other problems like the keyboard shortcuts only start to work when open the configuration window and not before... Mouse react after a very long delay... Sorry but > /dev/null

Ubuntu / Unity

My experience with the Ubuntu new Unity UI is just a nightmare for users like me who just want :

very light UI
very fast UI
Linux oriented UI

Finished !! Unity is just the total opposite : very slow (3 sec to open the menu... come on !), plus they just want to copy the Apple OS interface (why do you have to copy every piece of Apple : please be innovative !!)

After meeting a very annoying bug on the brightness tool on Mint on my laptop (this can happen), I wanted to try another distro, just because I like to see the new technologies.

Update: The brightness problem appeared from a linux header update on Samsung laptops only and is now fixed.

Debian

My last try was Debian, which is very popular too. I'm gonna say : this distro is taking me back to year 2000 !! The installation needs internet connection... and don't even propose to connect to the Wifi !!! After I realized this, I plugged my old ethernet cable (just for the installation !) and then launched again the installer. It took me 20 min to download the packages and at the middle of the installation, it just failed !!! Unbelievable ! Then once I rebooted, I could log in and then I couldn't use the best resolution on my laptop and the mouse was working very bad. Such a bad experience !

Update: Fedora review

Fedora 17

Well, Fedora 17 gave me a lot of good surprises ! The installation is neat, easy and the system is booting up quickly. After a few days of use, this is a little compare table :

+ Pros

Gnome Shell (the latest UI) is great, a bit too shiny for me
The system is very update to date (latest linux kernel versions)
Most packages are built for Fedora.
Easy to install Gnome Extensions (from your browser)

- Cons

Atl+Tab does not work with workspaces, so it's a total mess when you use (like me) lots of workspaces and windows. You have to use Alt+² for changing windows from the same applications (ooohhh!!!!)
Update: you can click on the "On" button on this page to enable the extension that install a "normal" Alt-Tab switching only for your current workpaces windows
https://extensions.gnome.org/extension/38/windows-alt-tab/
Fonts rendering is very bad. Even if you try to make it nicer, it never renders the correct font. When you work with Internet, this is very annoying and very had to fix on Fedora
Remember Kernel panics ? I bet you will see some of them with Fedora. How this could happen on Linux in these days ??
If you are used to apt-get, you will have to learn yum. That's not too hard, but there are still a lot of differences between these 2 packages manager so you will loose time to get the same packages installed on your system
SeLinux. Well this is a great project, until you realize that SeLinux is silently disabling features and so some apps may not work. As your system does not usually fail, you have to dig for hours to find the right solution and apply the correct rule for SeLinux. I ended up with disabling SeLinux because it's too secure for my laptop developer everyday usage.
Keyboard mapping fail. The login screen uses the root default mapping and not the user mapping... so when I log in, I have to switch my q with a in my password.... All the other distributions handle the keyboard mapping on the global system (and I didn't took time to look how to change the keyboard mapping for the root user, but I shouldn't have to do this).

For after been very well surprised by the Red Hat alternative to Linux Mint, I had a lot of bad experiences at a different level that make Fedora a bit hard for me to use (kernel panics, yum learning curve, selinux rules, alt-tab not limited to the workpace...)

Conclusion

The conclusion is that some distros are reaching the top by offering the best experience to the users. These guys understood that this point overcomes the geek details.
Linux culture is about to make everybody fell home with his Linux, so I split the user experience into these 2 categories

Innovation must not be jailed : Be innovative, but don't restrict the user from disabling these new features with the "basic and neat default feature" that just work perfectly !! (ex: you cannot disable Unity on Ubuntu / you cannot change how Alt-Tab is reacting...)
Give the quickest and easiest installation and give a user the everyday use easy : Installation must be done with anyone not knowing Linux or computers. The system must be very fast to boot, up to date with the latest software and most of all, no crashing bug should destroy your experience (my Ubuntu was logging me out when I moved the mouse on a picture in the browser, Fedora give me a lot of kernel panics...)

The main system OS fight (Windows, Linux, Apple) is not so active like before, now it's mobile OS war which is getting more and more popular. Apple won many battles in making the 2 previous points the best the user can reach comparing to Windows or Linux. I still think the war is not finished, especially for people that create software and have a heavy use of their system.

I ended up in installing Linux Mint Cinnamon again.

Linux Mint + Cinnamon is the best duo at this time

I still really love Linux and the different alternatives and there is not yet good enough reasons to use proprietary OS. This feedback will hopefully encourage to make Linux better, focusing on improving the overall user experience and not on creating geeky unusable tools.

Search / Run / View / Edit on very quickly on Linux with Synapse

2012-08-04T03:23:00.000-07:00

Synapse : You should have a look to this tool because it can save you a lot of time : no more click for running a term, launching the text editor for a specific file, start a search on Google... everything is at your fingertips with "Ctrl-Space" (by default).

sudo apt-get install synapse

Source: https://launchpad.net/synapse-project

Load frequent apps faster on Linux

2012-08-04T03:11:00.001-07:00

Preload is a daemon which monitors and track applications you run on Linux. So they can start up faster with it.

sudo apt-get install preload

Source : http://sourceforge.net/projects/preload/

Install Tahoma font for Linux

2012-07-25T03:56:00.004-07:00

Tahoma is actually a very common font used on many tools and web UIs. As a result, there is big change after you install it on your system.

As Tahoma is not included into the "ttf-mscorefonts-installer" package, the only way to get it is to download a .CAB file and extract it into your system :

download the IELPKTH.CAB package file (https://master.dl.sourceforge.net/project/corefonts/OldFiles/IELPKTH.CAB)

cabextract -F 'tahoma*ttf' IELPKTH.CAB
mkdir -p /usr/share/fonts/truetype/msttcorefonts/
mv -f tahoma*ttf /usr/share/fonts/truetype/msttcorefonts/
chmod 644 /usr/share/fonts/truetype/msttcorefonts/tahoma*
fc-cache -v
rm -f IELPKTH.CAB

Source: http://panic83.livejournal.com/19679.html

Find files from multiple names

2012-07-23T13:53:00.004-07:00

That is just as easy as :
$> find . -name file1 -or -name file2

Or you can go a bit further with multiples names and sortings:

selecting only directories for all match

$> find . $ -name file1 -or -name file2 $ -type d

selection directories only for the first test and only files for the second test

$> find . $ -name file1 -type d -or -name file2 -type f $

Remove undesirable Synology files with a script

2012-06-17T01:59:00.003-07:00

Just use this line to remove temporary files from Synology NAS : "@eaDir" folders and all kind of tmp files you want to remove

find /mnt/share/ -depth \( -name '@eaDir' -type d -or -name '.picasaoriginals' -type d -or -name 'Thumbs.db' -type f \) -exec rm -r -i {} \;

Let locate index files in your encrypted home folder

2012-03-16T09:28:00.000-07:00

If you cannot see your files when you search with the "locate" tool, you might have activated the encryption for your home directory. In order to push them in the index :

Edit /etc/updatedb.conf
Remove the entry "encryptfs" from the PRUNEFS variable
Run "sudo updatedb" in order to update the index

Launch Printer Tools with Ubuntu 11.10

2012-01-14T10:37:00.000-08:00

Just launch the system tool with

/usr/bin/python /usr/share/system-config-printer/system-config-printer.py

Uninstall VMWare Player on Linux

2012-01-13T06:40:00.000-08:00

Just rerun the installer, with the "-u vmware-player" option

sudo sh VMware-Workstation-Full-X.X.X-XXXXX.i386.bundle -u vmware-player

Source : http://ubuntuforums.org/showthread.php?t=1364485

Automatically change the screen brightness

2011-12-29T23:52:00.000-08:00

If you want to force a brightness level on your GNU/Linux, use the xbacklight tool:

sudo apt-get install xbacklight
xbacklight -set 0

Changer keyboard language mapping under ubuntu

2011-11-04T04:05:00.001-07:00

Easy, for instance to use the French layout keyboard :

loadkeys fr

Best audio encoder

2011-11-04T03:59:00.000-07:00

After many tries, XCFA is the perfect tool to encode your music.

Richard Stallman is true when he says: do not use proprietary formats because this force people use proprietary softwares.

I like :

easy and working very well
you can easily choose your codec and configure them
neat: you can choose the format of your files

Official website: http://www.xcfa.tuxfamily.org/

Play DVD with Linux

2011-10-09T15:08:00.000-07:00

Sometimes I don't really understand why so-easy task are not native yet to Linux !!!

Follow the few steps :

$> sudo apt-get install gstreamer0.10-ffmpeg gstreamer0.10-plugins-ugly gstreamer0.10-plugins-ugly-multiverse gstreamer0.10-plugins-bad gstreamer0.10-plugins-bad-multiverse

$> sudo /usr/share/doc/libdvdread4/install-css.sh

Source: http://www.debuntu.org/how-to-play-dvd-under-ubuntu-linux

Change the starting day in Gnome's calendar (Ubuntu)

2011-09-22T01:20:00.000-07:00

To change from Sunday to Monday as the starting week day, that's easy:

run the locale command to print the current system locale
edit /usr/share/i18n/locales/[your_locale] and change first_weekday to 2 (for Monday)
regenerate the locale using sudo locale-gen
restart the calendar, reloading it using killall gnome-panel

Source : http://soniahamilton.wordpress.com/2008/02/06/change-first-day-of-week-in-ubuntus-gnome-calendar/

Deploy your SSH public key to a server

2011-09-19T16:08:00.001-07:00

Easy with ssh-copy-id:

$> ssh-copy-id user@my_remote_server

Disable the 'stupid' thumbnails generation on Synology NAS

2011-09-07T00:27:00.000-07:00

Update with the DSM 5: the S77synomkthumbd.sh does not exist anymore.

In order to stop the automatic generation of thumbnails in your photos and movies directories, and also stopping your CPU + hard drive to be used non stop for these tasks for days and days...

Connect as root to your NAS with SSH

ssh root@your-nas-ip
vi /usr/syno/etc/rc.d/S77synomkthumbd.sh

Then edit the file and comment the line $SynoMakeThumb with a '#' at the beginning of the line.

Version 4: if you don't use "Photo Station" and the other tools that need indexing, you also have to disable the scripts:

/usr/syno/etc/rc.d/S66fileindexd.sh

Comment line with "/usr/syno/sbin/fileindexd"

/usr/syno/etc/rc.d/S66synoindexd.sh

Comment line with "/usr/syno/sbin/synoindexd"

You can kill the process, but try to reboot your NAS in order make sure you stopped the indexing process and make sure it won't come again (it will come again only after a DSM upgrade, so you will have to do it again because these files with be overwritten).

UPDATE: you can disable the indexing services by stopping them :

$> /usr/syno/etc/rc.d/S77synomkthumbd.sh stop
$> /usr/syno/etc/rc.d/S66fileindexd.sh stop
$> /usr/syno/etc/rc.d/S66synoindexd.sh stop

Then you can search for the temporary folders for deleting them