4.7. Debian and openMosix

Installing openMosix ``the Debian way'' can be easily done as described below.

The first step consists in downloading the packages from the net. I had to use a 2.4.19 kernel since the openMosix patches package is not yet available for 2.4.20 at the moment I write this. Since we are using a Debian setup we needed: http://packages.debian.org/unstable/net/openmosix.html, http://packages.debian.org/unstable/net/kernel-patch-openmosix.html, http://packages.debian.org/unstable/misc/kernel-package.html, http://packages.debian.org/unstable/devel/kernel-source-2.4.19.html. You can also apt-get install them ;).

The next part is making the kernel openMosix capable.

Basically, the procedure to follow is:
cd /usr/src
apt-get install kernel-source-2.4.19 kernel-package \
        openmosix kernel-patch-openmosix
tar vxjf kernel-source-2.4.19.tar.bz2
ln -s /usr/src/kernel-source-2.4.19 /usr/src/linux
cd /usr/src/linux
make menuconfig
make-kpkg kernel_image modules_image
cd ..
dpkg -i kernel-image-*-openmosix-*.deb
You now will need to edit your /etc/openmosix.map. Please follow the instructions given in the ``Syntax of /etc/openmosix.map'' part of this HOWTO.

After rebooting with this kernel and a configured /etc/openmosix.map, you should then have a cluster of openMosix machines that talk to each-other and that do migration of processes.

You can test that by running the following small script:
awk 'BEGIN {for(i=0;i<10000;i++)for(j=0;j<10000;j++);}'
a couple of times, and monitor its behaviour with "mosmon" where you will see that it spreads the load between the different nodes.

We also setup openMosixView on the Debian machine:
apt-get install openmosixview
In order to be able to actually use openMosixView you will need to run it from a user who can log in to the different nodes as root. We suggest you set this up using ssh. Please note that there is a difference between the ssh and ssh2 implementations. If you do have an identity.pub file, ssh will check authorized_keys, while if you do have an id_dsa.pub you will need authorized_keys2!

openMosixView gives you a nice interface that shows the load of different machines and gives you the possibility to migrate processes manually.

A detailed discussion of openMosixView can be found elsewhere in this document.