Proper use of CC at Lyon J. Brunner

Batch farm / bqs BQS classes Only for test jobs !! Regular Exceptional resource needs Very long jobs Large memory/scratch Regular Only on most powerful machines Try to split or group your scripts so that they fit into the regular classes If special queues needed : contact me

Batch farm / qsub options Specify precisely which resources are needed : qsub –l resource-list –t= : normalized CPU time –platform=LINUX32 : SL4 32 bit –M=512Mb : virtual memory –scratch=10000Mb : scratch size –hpss : access to HPSS –srb : use of SRB –oracle : acces of Oracle server at Lyon –u_srb_antares : Access to Antares SRB pool –u_xrootd : Use of XRootd server to acces Root files –u_sps_antares: use of Antares semiper disk space

Batch farm : HPSS/SRB It is forbidden to –Store small files on HPSS/SRB (< 100Mbyte) –Make multiple access to the same file from many jobs Forbidden means: jobs from users who are detected to perform operations like the ones above are blocked Maximal 50 jobs can access in parallel SRB/Antares Small files and multi-access files (e.g. scattering tables, noise files for TE) should be stored on $GROUP_DIR or on semiper disk space

Interactive machines ccali / ccalisl432 It is forbidden to –launch large scale productions and/or long jobs on these machines To be used only for interactive work (graphics, editing) or test jobs to prepare batch productions If observed behavior does not change, demons will be installed to kill interactive jobs which exceed certain (small) CPU time limits (e.g sec)

How to acces/store evt files SRB : Sput/Sget (/in2p3/mc, /in2p3/data) HPSS : rfcp ($ANTHPSS/users) SRB has larger buffer disks than HPSS, if you have a choice use SRB Intermediate storage of output files –$TMPBATCH (up to 16 GBytes) –Antares semiper space Same concept for output Root files

How to acces (read) Root files XRootd –Acces via XRootd server ccxroot –Large buffer disk –Faster than copy from HPSS/SRB to scratch –Replace file name of input root file by –root://ccxroot:1999//hpss/in2p3.fr/group/antares/ mc/neutrino/mu/l05_c09_s02/TE_3N_10pe/259 20/TE.MCEW.gea.anumu_lowe_109.root

Problems with XRootd When using with Root version earlier than 5.20 there are problems –Memory leak  virtual memory limit –Corrupted files Standard Root version at CC-Lyon 5.14 How to use 5.20 ? –Add following lines in your.cshrc before source $THRONG_DIR/group_cshrc –setenv ROOTSYS /usr/local/root/root_v /root –source /usr/local/shared/bin/root_env.csh –Use antares-daq, compiled with Root 5.20 like $ANTARES/src/DAQ_tree/Root_5.20_080902

Antares semiper disk space (new!) So far only $GROUP_DIR (afs) available to store files which are needed by many jobs, i.e. must be visible from many machines $GROUP_DIR total size 65 Gbytes Now GFPS space /sps/antares 2 TBytes –Not on afs, not visible from outside –Mounted on all interactive and batch machines –Direct acces (cp) or via rfio (rfcp), e.g. from HPSS User area /sps/antares/users –Create subdir with your login name mkdir /sps/antares/users/brunner –Use to store small files, frequent acces files –Use for temporary analysis files No disk quota introduced yet: Be reasonable !