Quick Reference

• UCSD - Hadoop
  • srm://bsrm-1.t2.ucsd.edu:8443/srm/v2/server?SFN=
  • dcap://dcap-2.t2.ucsd.edu:22140/
  • /hadoop/cms/store/user/mwlebour
• UCSD
  • srm://srm-3.t2.ucsd.edu:8443/srm/managerv2?SFN=
  • /pnfs/t2.ucsd.edu/data4/cms/phedex/store/user/mlebourgeois
  • dcap://dcap-2.t2.ucsd.edu:22138
• FNAL
  • srm://cmssrm.fnal.gov:8443
    • 11/pnfs
    • 2/mwlebour
    • resilient/mwlebour
  • /pnfs/cms/WAX
• CERN
  • srm://srm-cms.cern.ch:8443/srm/managerv1?SFN=
  • /castor/cern.ch/cms
  • /castor/cern.ch/user/m/mwlebour

Jake's Explicit dCache Tutorial

• First time users:
  • mkdir /pnfs/cms/WAX/2/< USERNAME >
  • Make sure that the group is us_cms: chown < USERNAME >:us_cms /pnfs/cms/WAX/2/< USERNAME >
  • Then make sure that it is group writable: chmod g+w /pnfs/cms/WAX/2/< USERNAME >
• Limit actions within /pnfs/cms/ to mkdir, rmdir, ls, rm, dccp and srcmp
• Don't cd in /pnfs/cms
• Don't run find commands
• Basically don't do any unnecessary access commands, dCache is on tape, and therefore slow.
• Do not trust ls.

Reading from dCache

• It is quite easy.
• It is easy to open files in dCache with ROOT just prefix the absolute path with a dcache:
  • or starting a new ROOT session: root dcap://dcopy-1.local:22138/pnfs/sdsc.edu/data3/cms/phedex/store/users/mlebourgeois/fileForAccessing.root
• To copy a file from dCache, do not you cp, use dccp.
  • dccp works just like cp, except that you are only allowed to specify one file at a time.
  • dccp is only used for copying files OUT of dCache, not into dCache

Writing to dCache

• You will need a GRID certificate to write to dCache so get one HERE.
• The best way to use it is to create a copyjobfile
• srmcp -copyjobfile=
• copyjobfile must have on each line a path for the HERE file and the THERE file
  • local files must be formatted as: file:///
  • dCache files must be prefixed with for FNAL: srm://cmssrm.fnal.gov:8443/2/< USERNAME >/ ...
  • dCache files must be prefixed with for UCSD: srm://t2data2.t2.ucsd.edu:8443/srm/managerv1?SFN=/pnfs/sdsc.edu/data3/cms/phedex/store/users/mlebourgeois/

• • /store/ files at
    • CERN: srm://srm.cern.ch:8443/srm/managerv1?SFN=/castor/cern.ch/cms/store...
    • FNAL: srm://cmssrm.fnal.gov:8443/11/store/...

UCSD Stuff

• Personal files: /pnfs/t2.ucsd.edu/data4/cms/phedex/store/user/mlebourgeois
• Read only PHEDEX: /pnfs/t2.ucsd.edu/data3/cms/phedex
• If doing high volume transfers, please create new (sub)subdirectories for every ~200 files. The most optimum file size is 1 to 2 GB. As you can expect, very small files, O(10 MB), but too many in number, may degrade performance. Thus, it is often recommended to pack them together for easy data/transfer management.
• srm://t2data2.t2.ucsd.edu:8443/srm/managerv1?SFN=/pnfs/sdsc.edu/data3/cms/phedex/store/users/mlebourgeois//

First Source

-- MatthewLeBourgeois - 05 Sep 2007