Athena Access to the SE

You can list files on the SE using either rfdir or dpns-ls:

rfdir /dpm/ph.bham.ac.uk/home/atlas/atlasmcdisk/mc08/
dpns-ls -l /dpm/ph.bham.ac.uk/home/atlas/atlasmcdisk/mc08/

Athena ultimately requires a list of files, so perhaps a script to take a DQ2 dataset name, find it's location on the SE and then output filelist.py would suffice?

Setup (User)

RFIO relies on the library libshift.so, but Castor and DPM required two different versions, Castor being the default. To fix this, in the run directory:

ln -s /home/lcgui/SL4/prod/lcg/lib/libdpm.so libshift.so.2.1
export LD_LIBRARY_PATH=`pwd`:$LD_LIBRARY_PATH

This allows for (the very slow) access to the SE using RFIO. Users will also require a valid grid certificate.

Finding Files

The sancho.sh script may be used to locate files on the SE via their DQ2 label. It can be used to output a filelist in two formats - with and without Athena decorations.

Example 1:

source sancho.sh mc08.105502.AcerMC_tchan.recon.AOD.e352_s462_r541           #Prints a list of files suitable with one file per line (suitable for ganga)

Example 2:

source sancho.sh -a mc08.105502.AcerMC_tchan.recon.AOD.e352_s462_r541       #Prints a list of files with Athena decorations ("ServiceMgr...." etc)

Testing

1. Where does data reside - se or sr? (netstat | grep 5001)
2. How fast is transfer? No idea how to do this. Produce nice histogram plots! Base line local disk access for 1000 events on worker nodes. Compare with different RFIO buffers.

-- ChristopherCurtis - 29 May 2009

• sancho.sh: sanch.sh - tool for finding files on the SE and printing filelists