segunda-feira, 2 de novembro de 2015

FERRAMENTAS LINUX: Aptik Backup dos seus temas, PPA e pacotes

Ao reformatar uma máquina com o Ubuntu para instalar outra versão do zero, um dos seus maior desafios é o de ter que reinstalar todas as aplicações, utilitários e ferramentas novamente.  Existem vários programas e scripts que se propõem a fazer isso, veja o opção do APTIK Backup no link:
FERRAMENTAS LINUX: Aptik Backup dos seus temas, PPA e pacotes

quinta-feira, 16 de julho de 2015

How to update Oracle Java on Ubuntu - faster then PPA releases

It usually takes a few days for a PPA repository to update Oracle JAVA releases.

You can solve this (for Debian based Linux distros) by making packages using "java-package" a few times (for various architectures), then distributing them internally.

If you don't have it installed open a console and type:

sudo apt-get install java-package

The big plus side is that this method always works; no matter how crazy Oracle's web pages become. Oracle can no longer break my build or stop my work, specially when Internet-banking depends on it!

The downside is that it's a bit more work to set up initially.

STEP-BY-STEP (ie. as the old music goes...)

1. Download the tar.gz files manually using your browser (ie. thus "accepting" their terms)

2. Run at prompt command:
         make-jpkg <java-package-name-xxx.tar.gz>.
   this will create a file named: "oracle-javaX-jXX_X_XXX.deb"
   Note that you may get some messages during the make-jpkg, just ignore them.

3. Distribute it within your organization (or your family devices)

For distribution over the Internet, I suggest using a password protected apt repository or provide raw packages using symmetric encryption:

passphrase="Hard to crack string. Use /dev/urandom for inspiration."
gpg --batch --symmetric --force-mdc --passphrase-fd 0 \
   oracle-javaX-jXX_X_XXX.deb <<< "$passphrase"

Of course providing (unencrypted) .deb packages on the internet is probably a violation of your license agreement with Oracle, which states:

    ... Oracle grants you a ... license ... to reproduce and use internally the Software complete and unmodified for the sole purpose of running Programs"

On the receiving end, if you have a password protected apt repo, all you need to do is apt-get install it. If you have raw packages, download, decrypt and dpkg -i them.

Works like a charm!


sábado, 11 de julho de 2015

How to Increase RAM available to Raspberry Pi CPU or GPU

Raspberry Pi 2 has 1,024MB RAM that is partitioned between the CPU and the GPU. If the Pi is working as a headless server or the Pi desktop is being accessed via VNC (which doesn't utilize the GPU) the memory split between the two processors can be altered to assign more memory to the CPU for running applications.
  • Default GPU memory on Raspbian is set to 64MB and the minimum recommended to ensure proper operation is 16MB.
  • Pi Camera Module requires a minimum of 128MB RAM.
  • Kodi Media center requires a minimum of 256MB RAM for the GPU, to avoid choppy video playback.
To modify GPU memory to 256MB either:
  1. edit /boot/config.txt and set gpu_mem=256;
  2. run sudo raspi-config and select option 8 Advanced Options -> A3 Memory Split and modify value to 256
Save the change, reboot the Pi, and enjoy the CPU memory boost!

quinta-feira, 12 de fevereiro de 2015

Can't remote access lubuntu server with Vino but connection with ssh works.


Can't remote access lubuntu server with Vino but can ssh it.


You open a ssh tunnel (map remote 5900 port to local 12345 port) of remote lubuntu station (ex: at terminal client side to remote access lubuntu station.

Example to type at cmd prompt:
 ssh -L 12345:localhost:5900 user@

         note: change "user" and address ( with your own ID.

You open a second terminal window at client station to start vnc with cmd:
xvncviewer localhost:12345

Error msg client side:
xvncviewer: VNC server closed connection

Error msg server (the ssh terminal) side:
channel 3: open failed: connect failed: Connection refused


Vino-server not running


At cmd prompt type (remote server side):
export DISPLAY=:0.0

Error msg:
Connected to RFB server, using protocol version 3.7
Server did not offer supported security type


server encryption scheme not understood client side


At the remote lubuntu server side set encryption variable to false

cmd prompt type:
gsettings set org.gnome.Vino require-encyption false