This support solution is on installing a 32-bit app on a x64 system. Stated on the example of Java Development Kid installed on Fedora x64 bit.
There are three layers that are important when it comes to 32/64bit compatibility:
- Processor
- Operating System
- Application
A 32 bit OS will run on a 32 or 64 bit processor, without any problems.
A 32 bit software on a 64 bit OS works, but could cause difficulties even if the 64 bit systems are backward compatible
with the 32 bit counterparts.
To run a 64 bit OS, you need support from its lower level (a 64 bit processor). Therefore a 64 bit OS does not work for a
32 bit CPU.
To run a 64 bit application, you need support from all lower levels (64 bit OS and 64 bit processor).
Linux commands:
Check your processor:
# cat /proc/cpuinfo
Check Kernel/System:
# uname -m
For our example, the perfect solution is to install a 64 bit version of JDK on the Fedora x64 bit operating system.
Here is the How-To-Do:
First thing we need to do is get the JDK installer
JDK Home from Oracle.com
Once we have the installer in our local repository (as root):
chmod a+x jdk-6u21-linux-x64-rpm.bin./jdk-6u21-linux-x64-rpm.bin
Next, we must add these two lines to the file: /etc/profile
JAVA_HOME=/usr/java/jdk1.6.0_21 pathmunge $JAVA_HOME/jre/bin after
At the end of the line that starts with export, we need to add this our JAVA_HOME variable, so the line should be like this:
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC JAVA_HOME
Then, we need to execute the next statements. Hint: Copy all the lines like if were just one.
export JAVA_HOME=/usr/java/jdk1.6.0_21 export JAVA_ALTERNATIVE_PRIORITY=16021 /usr/sbin/update-alternatives --install /usr/bin/java java $JAVA_HOME/bin/java $JAVA_ALTERNATIVE_PRIORITY /usr/sbin/update-alternatives --install /usr/bin/javadoc javadoc $JAVA_HOME/bin/javadoc $JAVA_ALTERNATIVE_PRIORITY /usr/sbin/update-alternatives --install /usr/bin/appletviewer appletviewer $JAVA_HOME/bin/appletviewer $JAVA_ALTERNATIVE_PRIORITY /usr/sbin/update-alternatives --install /usr/bin/javah javah $JAVA_HOME/bin/javah $JAVA_ALTERNATIVE_PRIORITY /usr/sbin/update-alternatives --install /usr/bin/javac javac $JAVA_HOME/bin/javac $JAVA_ALTERNATIVE_PRIORITY /usr/sbin/update-alternatives --install /usr/bin/jar jar $JAVA_HOME/bin/jar $JAVA_ALTERNATIVE_PRIORITY
Then, we export the alternatives:
/usr/sbin/update-alternatives --auto java /usr/sbin/update-alternatives --auto javadoc /usr/sbin/update-alternatives --auto appletviewer /usr/sbin/update-alternatives --auto javah /usr/sbin/update-alternatives --auto javac /usr/sbin/update-alternatives --auto jar
To confirm that our installation is successfull:
java -version
Should give us an ouptput like this:
[[email protected]]# java -version java version "1.6.0_21" Java(TM) SE Runtime Environment (build 1.6.0_21-b02) Java HotSpot(TM) 64-Bit Server VM (build 16.3-b01, mixed mode)
Further information:
http://www.techsupportalert.com/content/32-bit-and-64-bit-explained.htm
http://wporta.wordpress.com/2010/07/06/installing-jdk-in-fedora-13/
