Image Magick Tips and Tricks:

In order to convert large images one can limit the memory of convert process.
Also if your /tmp folder is not big enough you can specify swap directory from command line:

convert -limit memory 320000mb -monitor -debug cache -define registry:temporary-path=/scratch/02tmp tileimg.ppm tileimg.mcp

If convert has an OpenMP palatalization enabled you can set number of threads with:

-limit thread 1

For 48000x48000 image   it uses about 900Gb for caching.
In example I use mcp native imagemagick cache format. If same image will be analysed/converted many times this format is recommended.

Files Meta: Yet another OwnCloud app

the main idea of this app is to get an information who was sharing this file with you and what kind of  data is it. just some simple text description is stored in database. The concept can be expanded in order to store an   arbitrary information per file: key=>value pairs using name spaces

download Files_Meta

Owncloud app is released: latex Editor and Compiler

here is my first app for owncloud OC4.01 :
Download

Actually I just tested with OC5.0 from git and it is working!!
APP needs to have an access to /tmp/ folder where he will generate per latex file folder where he  will compile and generate pdf.
It require that on server you have pre-installed pdflatex, miktex libraries.
here some screen shots:Screenshots

Headless installation of virtualgl.

After installation of virtualgl on CentOS 6.2 one need to be sure that main X.org is starting without monitor.
Without that the vglrun throws an error unable to connect to display :0
The reason is xorg is not started due to the monitor. The monitor is detached.
You cannot keep one monitor per cluster node if you want to run rendering farm of 1000 GPUs.
So the solution is to run nvidia driver in headless mode!!!
After Nvidia official driver installation run following:

 
nvidia-xconfig -a --use-display-device=None --virtual=1280x1024

reboot it.
Then the in the vnc connection simply run:

vglrun glxinfo| grep -i renderer 

You should see your GPU string information: in my case is Tesla 2050

CentOS 6.2 unable to update using yum!!!

The CentOS 6.2 was unable to update using yum due to failure on system, I did accidentally reboot during the update process.  Then I discovered that yum unable to update with following error:

... Many errors and some concerning glibc

You could try using --skip-broken to work around the problem

It does not help it was claiming that:
glibc is protected_multilib
To fix:

yum clean all

package-cleanup  --cleandupes


yum check-update

yum update --setopt=protected_multilib=false --skip-broken

WiFi Scanning on Ubunty? Its soo easy!!!

In order to scan documents on Ubunty 12.04 you should install:
I have a Epson Wifi SX425w printer. On Epsons web site I was able to find debian package for the drivers. Using dpk I installed them.
Next step:
Install XSane Image Scanner.
run Xsane anad enjoy it!
Ubuntu 12.04 rocks (besides on many troubles on my Sony laptop) 

Ubuntu 12.04 desktop trouble it is empty.

After messing up the compiz setting the desktop was empty. In order to fix it one should press: Ctrl+Alt+F1 to get terminal then in terminal run:
bash~# unity --reset
It will bring the default unity configuration.
And Enjoy Ubunty 12.04LTE!!!

 

in order to run virtual machine on linux use this:


/usr/libexec/qemu-kvm -hda AN-cloud1.qcow -hdb an-cloud1-srv.qcow -boot c -cpu host -smp 2 -m 2048 -net nic,macaddr=DE:AD:BE:EF:FD:A2 -net user,hostfwd=tcp::20022-:22,hostfwd=tcp::20080-:80,hostfwd=tcp::20033-:3306 -vnc :9 -usbdevice tablet