# Computing Guide ## Introduction EPP computing resources include the following: Linux desktop machines Linux interactive machines Batch job service Network file stores Grid computing service Backup service Printing service ## Support EPP computing support is provided by Peter and Alex. Please e-mail Peter in the first instance or drop by our offices on B-floor. Messaging via TEAMS is also fine. ## Accounts User accounts may be requested by filling out [ this Google form](https://docs.google.com/forms/d/11rZI5qLSqeAd2nx7hCuSBE4WtVp2DiIM6L_y02nfVm4/edit). This account is valid on any machine in the cluster. You will be assigned to a group corresponding to one of our recognised experiments. Currently these are ATLAS, DØ, HyperK,  LAr, SNO+, and  T2K . You will have a home area on the corresponding disk, and access to the software of that experiment. ## Changing passwords If you wish to change your password type the following command on any cluster machine. You will need to pay attention to the prompts and enter your current password twice. $ passwd ## Desktop machines HEP desktop machines run Alma Linux version 9 and are a general purpose Linux desktop for both physics analysis and admin work. ## Interactive machines There are currently three interactive machines  which may be access from anywhere on the internet. They are running Alma9 Linux and are well specified with many cores and large memory. Grid User Interface (UI) software is available on these machines and they are mainly used for code development, analysis, and submitting jobs to the batch system and Grid. The machines are: - `lapw.lancs.ac.uk`   (Alma9) - `lapx.lancs.ac.uk`   (Alma9) - `lapz.lancs.ac.uk` (Alma9) ## Personal laptops Personal laptops may be connected to the network but must be registered with the ISS PASS system. Access to HEP resources will then be via ssh to the interactive machines. ## Learning There are copious Linux command line tutorials on the web and ChatGPT has learnt them all. ## Batch system To be updated. In the meantime please check [Quick Start](https://slurm.schedmd.com/quickstart.html) and other docs. ## Grid computing Grid users should apply for an x509 certificate here: http://www.ngs.ac.uk/ukca/certificates ATLAS users can request membership of the ATLAS Virtual Organisation here: https://atlas-auth.web.cern.ch/login      (also request /atlas/uk group) ## ATLAS client tools ATLAS client tools can be setup from cvmfs. It's recommended to add these to your ~/.bash_profile file. export ATLAS_LOCAL_ROOT_BASE=/cvmfs/atlas.cern.ch/repo/ATLASLocalRootBase alias setupATLAS='source ${ATLAS_LOCAL_ROOT_BASE}/user/atlasLocalSetup.sh' Then you can run the setup command: $ setupATLAS You may then use the rucio data management commands: $ lsetup rucio --quiet ## Backup It is important to realise that only the /home areas are backed up, so if you put critical irreplaceable file on the data disks or anywhere else, you do so at your own risk. The backup is run every night so we can generally help you recover accidentally deleted files, or old version of files up to 3 months in the past. After this period backups are rotated so we will be unable to help. ## Email The university provides webmail and MS-Exchange email through ISS. Details for Thunderbird are here. The Exchange email server name: exchange.lancs.ac.uk Your SMTP address - on campus this is: smtp.lancs.ac.uk Maillists To view maillists, membership details, and to subscribe go to maillist main page: https://lists.lancaster.ac.uk Relevent lists are: physics-epp-staff physics-epp-mphys physics-epp-phd physics-epp-atlas physics-epp-neutrinos physics-epp-t2k ## Printing ISS-managed printers are available on B-floor in B22 and also at the east end of the corridor. Instructions to setup these printers for Windows, MacOS, and Linux are available on the [ISS web pages](https://print.lancaster.ac.uk). ## Video and phone conferencing We have a dedicated video conference/phone conference room in B07 however most experiments now use their own systems. Please refer to your experiment's documentation. ## Web Browsing Firefox is available on the Desktops. ## Email Clients Please see the ISS email page for further information. ## Editing A variety of text editors are available on the linux systems. For example vim, nedit, gedit, pico, and even emacs for the brave. ## Compiling Fortran, c and c++ programs are compiled and linked using gcc. ## Text processing Use pdflatex. ## External access to the cluster Secure shell terminal access (ssh) To log into the cluster from outside you will need to use secure shell , either the command "ssh" on a Unix machine or using the program "putty" on a windows machine. ## Web pages Each user is free to create his own directory ~/public_html/ in which he can place web pages. These will appear to the outside world as https://hep.lancs.ac.uk/~ajf/ (where ajf is your username for example).