Using RFIO or DCAP to access files on Nikhef Grid disks

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Revision as of 11:09, 8 February 2008 by Fkoetsve (talk | contribs) (Created DCAP?RFIO Howto)
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Since in principle all AODs will be stored in Nikhef's basement, it is convenient to use a system that allows us to access these files from our desktops, or the stoomboot cluster. NFS will not work, because it cannot handle many parallel large data transfers. Different protocols have been developed to accomodate this. The nikhef DPM (Disk Pool Manager) uses RFIO, sara uses DCAP(Data Link Switching Client Access Protocol). To access these files, the root GFAL (Grid File Access Library) plugin can be used. Access using RFIO/DCAP is simple, but there are a few issues.

"Setting up use of DCAP/RFIO: Shell"

A few environment variables have to be set. In bash: 

#To setup the GRID DQ2 tools run setup_grid_tools
source /global/ices/lcg/current/etc/profile.d/grid_env.sh
export LFC_HOST='lfc03.nikhef.nl'
export LCG_CATALOG_TYPE=lfc
export LCG_RFIO_TYPE=dpm
export  X509_USER_PROXY=$HOME/.globus/gridproxy.pem

Where the last cariable is set to store look for your grid proxy in a place accessible from stoomboot. Use the following options with "voms-proxy-init": 

voms-proxy-init -voms atlas -order /atlas/nl -out $HOME/.globus/gridproxy.pem
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