Tips und Tricks for Palma

Freigeben von Verzeichnissen für andere Nutzer per ACL

Sometimes, acces to your files should be granted to other users. If they are not member of your own group, the directory has to be made world-readable. A more fine granular acces control can be realized with so-calles ACLs. The commands "getfacl" and "setfacl" enable it to give individual users read and write permissions to specific files. A detailed description of these commands can be found here: ACL with Linux.

I want to login from different computers to palma and do not want to open serveral ssh-connections every time

In this case use the Login via vnc. Even after closing the vncviewer, the session remains open.

Why is my MPI program that slow?

MPI programs are sometimes slowed down by too many communication. Tools like the Intel Trace Analyzer will help to determine this. If you use Intel-MPI, just load the module "intel/itac" and link the code with the switch "-trace":

module add intel/mpi
module add intel/itac
mpiicpc -o democode democode.cpp -trace -O3

Execute the program as usual via the batch-system. After finishing the run, there are different files with the suffix .stf.*. These can by analyzed with the traceanalyzer:

traceanalyzer Programmname.stf

Because of the GUI, you have to enable the X-forwarding while establishing the ssh connection (and start a local X-server like xming, if you run Windows). In Linux, use the switch -X, in putty, you habe to "Enable X11-forwarding".

The complete manual can be found here.

-- HolgerAngenent - 2010-08-16