Simulations

We have provided some script to make your life a bit easier!

List machines

To see a list of available machines in TELIN, their OS version, CPU type, CPU speed (GHz) and the build in RAM memory (MB), you can issue the following command (the list is sorted from fastest to lowest CPU speed):

$ machines

Check availability

If you plan to start a simulation, it’s better to check which CPU is the fastest, but also how many simulations are already running on a particular machine e.g.: If you have a 2000 MHz core CPU, and 4 simulations are running concurrent, in the best case every simulation is assigned 500 Mhz. Thus if you run a simulation extra, your simulation will be assigned only 400 Mhz. An older computer with a 600 Mhz core will run your simulation 13 faster (if only 1 simulation is assigned). To account for all of this (plus the fact we have now multicore systems!) and to figure out what is your fastest machine, you can start a simulation with the script:

$ nextsim

It will generate a sorted list from low to high, with the available CPU speeds. Thus the machines mentioned last will be the best choice (column 1 = speed, column 2 = machine) for you!

No hangup

If you want to run your simulations in background you will be able to log out without your simulations being stopped if you use nohup (no hangup). The safest way is to redirect all standard file discriptors stdin, stdout and stderr. Suppose your program is called “doit” and needs arguments “-q 0 test.avi”. You can issue the following command:

$ nohup doit -q 0 test.avi </dev/null >& result-doit.txt &

Some programs read from a text input file e.g. maple:

$ nohup maple < maple-script.mpl >& result-maple.txt &

Check your running programs

You can check your running programs on a Linux lab computer with:

$ ps ux
# or
$ top