Grid For Dummies:
A step by step introduction for stupid users like me
Before anything else
Before doing anything else you will have to get a grid certificate: http://grid.desy.de/certs/#_intro_ and become member of an virtual organisation (VO): http://grid.desy.de/certs/#_vo_ .
Once you succeeded with these very first administrative steps, put your certificate into your afs directory. And now you can start to use the grid!
First steps
You can create an shell script to set the grid environment like attachment:start_grid.sh
Copy the attached script into your afs directory and execute it:
$ . start_grid.sh
Afterwards you need to initialize a grid proxy
$ voms-proxy-init --voms calice --valid 168:00 $ Enter GRID pass phrase:
And you should get a message like:
Your identity: /O=GermanGrid/OU=DESY/CN=Nanda Wattimena Creating temporary proxy ........................................ Done Contacting grid-voms.desy.de:15102 [/C=DE/O=GermanGrid/OU=DESY/CN=host/grid-voms.desy.de] "calice" Done Creating proxy .................................................... Done Your proxy is valid until Wed Mar 19 14:47:18 2008
This proxy will be valid for the VO calice (voms = virtual organisation membership service) for the next 168:00 hours, so practically for ever.
In case you want to check your proxy just type:
$ voms-proxy-info -all
Once you are done don't forget to destroy your proxy! Otherwise other people might abuse it.
$ voms-proxy-destroy
Getting informations
To have a look what is available try
$ lfc-ls /grid/calice/tb-cern/sim/test_prod
to list a file cataloge, or
$ lcg-infosites --vo calice ce $ lcg-info --vo calice --list-ce --attrs TotalCPUs,MaxCPUTime,MaxWCTime
for informations about info about computing elements (CE), sites, ...
Copying from / to the Grid
To get a file from the grid:
$ lcg-cp -v --vo calice lfn:/grid/calice/tb-cern/rec/rec_v0405/log/therec.steer.321071.tar.gz file:$PWD/therec.steer.321071.tar.gz
This will copy the file therec.steer.321071.tar.gz from the grid path therec.steer.321071.tar.gz to your current directory.
To put a file into the grid:
lcg-cr -v --vo calice -d srm://srm-dcache.desy.de/pnfs/desy.de/calice/tb-cern/sim/test_prod/desy/Mu_100GeV_100000evt_TBCern07.tgz -l lfn:/grid/calice/tb-cern/sim/test_prod/desy/Mu_100GeV_100000evt_TBCern07.tgz file:/pool/nwattime/Mu_100GeV_100000evt_TBCern07.tgz
This will put the file: Mu_100GeV_100000evt_TBCern07.tgz from the directory: /pool/nwattime/ to the DESY dCache: /pnfs/desy.de/calice/tb-cern/sim/test_prod/desy/ and make it available from the Grid path: /grid/calice/tb-cern/sim/test_prod/desy/
Running jobs on the grid
In case you really managed to run a job on the grid, here are some more useful commands:
$ glite-wms-job-status -i JobID.jid
shows the job status.
$ glite-wms-job-output --noint --dir $(pwd) -i JobID.jid
gives you an output sandbox, and
$ glite-wms-job-cancel --noint -i Mokka.jid
will cancel the job on the CE.