How to check memory size of each process

use top or htop or ps vax|sort -k8n

missing libudev.so.0 when launching chrome, chromium or dartium in ubuntu

sudo ln -s /lib/x86_64-linux-gnu/libudev.so.1.3.5 /usr/lib/libudev.so.0

How to supporess Picked up JAVA_TOOL_OPTIONS Picked up JAVA_OPTIONS Picked up _JAVA_OPTIONS

Picked up JAVA_TOOL_OPTIONS:
Picked up _JAVA_OPTIONS:

These lines appear before any java program execution, if the environment variables with these names were set.  Remove it to supporess these ugly lines.

Windows:

set JAVA_TOOL_OPTIONS=

Linux

bash (default for Ubuntu, Debian, Redhat, CentOS, etc.)

unset JAVA_TOOL_OPTIONS

Install latest maven from apache

Since Ubuntu's repository comes with rather old version of maven, we need to install this from binary download from apache web site.

Here, we install latest version of 3.2.x which is 3.2.5 at the moment.
(linux diredory layout http://www.nixtutor.com/linux/understanding-the-linux-directory-layout/ )

Download from http://maven.apache.org/download.cgi

Install to /usr/lib/apache/maven/3.2.5

sudo mkdir -p /usr/lib/apache/maven/3.2.5

cd /usr/lib/apache/maven/3.2.5

sudo tar xvf ~/Downloads/apache-maven-3.2.5-bin.tar.gz

sudo mv apache-maven-3.2.5/* .

sudo rmdir apache-maven-3.2.5


Then we need to set environment variables.

add /usr/lib/apache/maven/3.2.5/bin to PATH

export MAVEN_HOME=/usr/lib/apache/maven/3.2.5



If we set environment variables in .bashrc, we will need to source the .bashrc file.

. ~/.bashrc

Check with :

mvn -ver

How to mount an lvm, volume from ubuntu livecd

Install lvm2 tool, if the distribution cd does not have it.  For 15.04, it's already there.
 
apt-get install lvm2

fdisk -lu

 
pvscan

vgscan

vgchange -a y


lvscan


Now, mount the volume to any directory you want.
 mount /dev/VolGroup00/LogVol00 /mnt