Doctoral researchers guide

This guide details some of the information you will need to conduct your studies efficiently. It concentrates on aspects of CMS computing (as that’s our major project) and assumes you have registered with the University, have arranged a supervisor and have acquired a University computing account and an ID/access card – all of these things normally happen immediately after you arrive.

High Energy Physics (HEP) Group personnel

Prof. Akram Khan – Professor / Public Engagement Ambassador. Head of group.
Prof. Peter Hobson – Honorary Professor. Formerly head of group, now at Queen Mary University but a frequent visitor.
Dr Joanne (Jo) Cole – Senior Lecturer
Dr Paul Kyberd – Senior Lecturer
Dr Liliana Teodorescu – Senior Lecturer
Dr David Smith - Reader
Dr Ivan Reid – Research Fellow II. Ivan maintains our computing infrastructure as a sideline
Dr Raul Lopes – Research Fellow. Raul maintains our large computer farm which is used by researchers world-wide as part of “The Grid”. He also works part-time at JISC, the body tasked with providing networking and other computer infrastructure for educational, research, and other institutions nationwide.

Things you will need to possess or acquire

(See The CMS Workbook Twiki for more details)

Familiarity with the Linux operating system, and some proficiency in the C++ and python computer languages.
Your own OpenSSL public/private key files, to allow access to our machines.
Membership at CERN. See the CERN Pre-Registration Tool.
Registration in the CMS Collaboration (ask your supervisor for help with this).
A computer account at CERN.
A personal certificate to identify yourself on the GRID. This will normally be obtained through the UK Certification Authority Portal but you can also obtain a certificate from CERN with your account there. You will need to visit Raul with suitable identification (e.g. passport) for your initial registration for a UK certificate.
Registration with the CMS “virtual organisation” (VO) – follow the instructions How to register in the CMS VO.
The Cisco AnyConnect virtual private network (VPN) software, obtainable from the Brunel Connect Portal to allow you to connect to computers within the BUL network from home and elsewhere.

Working with our servers

We maintain several dual-CPU computing servers at present:

pion – 20 cores, 128 GB of RAM, and a total of 30 TB of local storage.
pion2 – an older machine, used mainly as a “squid proxy” to cache file access requests to outside servers
cgmd-s6 – 12 cores, 64 GB of RAM, 22 TB local storage.
cgmd-s7 – a very old machine, with 15 TB of RAIDed storage, available from all other servers over NFS for backup and archiving.
brphac – 40 cores, 128 GB of RAM, 2 TB local storage.

All machines, except brphac, run obsolete operating systems based on Red Hat Enterprise Linux 6; these must be upgraded to Centos 7 as soon as the pandemic allows. As well as storage available over NFS, the servers can also access the cvmfs file system, allowing access to software served out of CERN and elsewhere around the world with caching on pion2 to speed up multiple requests for the same data.

To obtain an account on one of our servers, please come to see me, bringing your OpenSSL private key on a USB drive. We can then discuss which server(s) you will need to access and I can create account(s) as required. Note that your account(s) will have the same name as your central Brunel account (i.e. eepgxxx), and that login is only available via ssh using your OpenSSL credentials. OpenSSL keys are kept in your ~/.ssh subdirectory.

To work with the GRID, your personal certificate needs to be installed in a subdirectory ~/.globus as a file called usercred.p12.

To use the CMS software you need to set up the environment for each login session. This is done using the command source /cvmfs/cms.cern.ch/cmsset_default.sh

CMSSW work areas are set up with the cmsrel command, and the proper environment set for each area with the cmsenv command – see the Workbook Twiki for more information.