Working with the LRZ SuperMIC system

This is to get you to the point where you can do useful stuff on the LRZ SuperMIC system: Logging in via ssh, submitting jobs, using the compilers.

Detailled information on the SuperMIC system can be found under: http://www.lrz.de/services/compute/supermu/supermic/ 

After switching on the Windows-XP based PC's in the exercise room, you will be automatically logged in. From there you can log in to SuperMIC as follows, using the accounts and password provided by the LRZ staff.

• Click on Windows symbol on left bottom and type into the field "Programme und Dateien durchsuchen:
  xming and after that PUTTY to start those 2 applications
• Enter host name training.srv.mwn.de into the putty host field and click Open.
• Accept & save host key [only first time]
• Enter user name and password (provided by LRZ staff) into the opened console.
• Login to SuperMIC with "ssh -X supermic.smuc.lrz.de".
• Start at least 3 xterms via "xterm &"
• Run ". /etc/profile.d/modules.sh" to initialise the module system in the opened windows.
• Please copy the source code for the exercises to your home directory:
  cp -ra /lrz/sys/courses/gpu_mic/ $HOME
• This directory has subfolders, which contain skeleton codes and makefiles for several example codes you will work on.
• The SuperMIC login-node (login12) must be used for editing and compiling your code and possibly for short testing; please do not perform long runs on these nodes as this will disturb user operations. Moreover, many users are active on the frontends and you will not get sensible performance data anyway.
• To access the SuperMIC compute nodes interactively, do the following:
  • Enable password-less login via the following commands:
    • ssh-keygen
    • cat ~/.ssh/id_rsa.pub  >> ~/.ssh/authorized_keys
  • An example job file can be found under /lrz/sys/courses/gpu_mic/job.ll
  • Submit the job via: llsubmit job.ll
  • Find out the compute node which has benn allocated by running: llq -u $USER
  • Login to the compute node via e.g.: ssh -X i01r13c08
  • The compute nodes should not be used for compiling your code, since e.g. include files or libraries are not installed there.
  • Kill the job via "llcancel jobname"
• To access the SuperMIC compute nodes non-interactively replace the "sleep ..." in job.ll by the program you want run non-interactively. You might need to load appropriate modules in the jobfile before running your application.
  
  
• Version 15.0 of the Intel compilers is automatically loaded at login. The Intel compilers are called icc (for C), icpc (for C++) and ifort (for Fortran). They behave similar to the GNU compiler suite (option –help shows an option summary). For reasonable optimization including SIMD vectorization, use options –O3 –xHost (you can use -O2 instead of -O3 and sometimes get better results, since the compiler will sometimes try be overly smart and undo many of your hand-coded optimizations). By default, OpenMP directives in your code are ignored. Use the -openmp option to activate OpenMP.