StashCache area for ICARUS

The StashCache mechanism is explained in its own entry in the FIFE wiki.

Suffice to say, ICARUS does have such a facility available, and the data can be accessed from the paths:

• /cvmfs/icarus.osgstorage.org/pnfs/fnal.gov/usr/icarus/persistent/stash (recommended?)
• /pnfs/icarus/persistent/stash

Writing data into StashCache

Directory /pnfs/icarus/persistent/stash is owned by the collective user icaruspro. For a user to be able to write in there, she can either:

• log in a dCache-aware node (e.g. an ICARUS GPVM) as icaruspro via

  ssh icaruspro@icarusgpvm.fnal.gov

  using Kerberos authentication; this works only if that user is authorized to present herself as icaruspro (which translates into her Kerberos principal user@FNAL.GOV being listed in ~icaruspro/.k5login file)

• use IFDH (ifdh cp) to copy directly the data; this requires a grid certificate proxy with role Production (the usual role is Analysis), and again this role must have been explicitly granted to the user.

Accessing StashCache

ICARUS General Purpose Virtual Machines are already configured to access StashCache both via /pnfs and via /cvmfs paths (the former can be turned into a XRootD URL).

Other systems can access it via CVMFS using the path described above. Instructions are available to enable CVMFS on a machine.