9.3. Optimizing Mosix

Editorial Comment: To be checked with openMosix versions

Login a normal terminal as root. Type

setpe -r

which, if everything went right, will give you a listing of your /etc/mosix.map. If things did not go right, try

setpe -w -f /etc/mosix.map

to set up your node. Then, type

cat /proc/$$/lock

to see if your child processes are locked in your mode (1) or can migrate (0). If for some reason you find your processes are locked, you can change this with

echo 0 > /proc/$$/lock

until you fix the problem. Repeat the whole configuration scheme for a second computer. The programs tune_kernel and prep_tune that Mosix uses to calibrate the individual nodes do not work with the SuSE distribution. However, you can fake it. First, bring the computer you want to tune and another computer with Mosix installed down to single user mode by typing

init 1

as root. All other computers on the network should be shutdown if possible. On both machines, run the following commands:

/etc/init.d/network start /etc/init.d/mosix start echo 1 > /proc/mosix/admin/quiet

This fakes prep_tune and the first parts of tune_kernel. Note that if you have a laptop with a pcmcia network card, you will have to run

/etc/init.d/pcmcia start

instead of "/etc/init.d/network start". On the computer you want to tune, run tune_kernel and follow instructions. Depending on your machines, this can take a while - if you have a dog, this might be the time to go on that long, long walk you've always promised him. tune_kernel will create a program called "pg" in /root for testing reasons. Ignore it. After tuning is over, copy the contents of /tmp/overheads to the file /etc/overheads (and/or recompile the kernel). Repeat the tuning procedure for each computer. Reboot, enjoy Mosix, and don't forget to brag to your friends about your new cluster.