Particle Physics Linux Systems Background

The general purpose Linux login servers are pplxint12 and pplxint13, running Enterprise Linux 9 (EL9) operating system.

These interactive servers gives access to a HTcondor batch system running several EL9 worker nodes. All machines remain switched on except for during minimal maintenance periods.

In case of software or hardware problems, the system may have to be taken down at short notice. Any problems should be directed to

Access to all Unix systems (except pplxintn) from outside of the domain is disabled. When you are away and wish to connect, login to pplxintn, then on to the others if needed. You can only use ssh. This avoids hackers "sniffing" your passwords.

Please refrain from running compute/memory intensive processes on pplxint12 or pplxint13. Please use the batch system Condor Batch System.

If it is absolutely necessary, long, CPU intensive, single threaded jobs may be run "niced", eg,

nice ./

Jobs that are left running using large amounts of CPU/memory on the interactive servers may have the priority lowered or be killed without notice.

Please do not run jobs which use high network bandwidth for long periods or that heavily hit the disk system. This helps keep interactive response acceptable. It is unlikely that groups other than SNO, T2K, Atlas and LHCb need to worry about internal network or disk access impacting interactive performance.

We keep a pool of third-party software on the systems. You can obtain a list of (recently) installed 3rd party software using the command "module avail". The software environment must be "loaded" before the software is "executed". To load the environment use "module load". The software can then be executed, e.g. to load and execute Geant4 version 11.1.0:

module load geant4/11.1.0

You may ask for additional software to be installed by contacting us at the address above. This software may also be made available on the University cluster, ARC. All Members of the university may access this supercomputer which is running a very similar system to us.

Categories: Linux | PP | Particle | Unix | ppunix