There are currently 14 CVMFS opensciencegrid.org repositories hosted at Fermilab that are available to the Open Science Grid, to all sites that have an OSG installation of the cvmfs client. There are now also five repositories -- fermilab, lsst, mu2e, nova, and uboone -- that are available to any site worldwide that has installed a standard cvmfs client from CERN or EGI in the last year.
CVMFS clients read data from Stratum 1 servers, and there are five of those worldwide in the default client configuration for the opensciencegrid.org domain (see map). Two of them -- at Fermilab and BNL -- are also used within the OSG, so all opensciencegrid.org repositories are on those. Worldwide clients could read long-distance from those, but in addition to increased latencies, due to a limitation of the cvmfs automated ordering randomly choosing 3 servers to calculate an order, sometimes those mounts will fail.
EGI has a documented process https://wiki.egi.eu/wiki/PROC20 for importing opensciencegrid.org repositories to the other 3 Stratum 1s. EGI first requires that a VO be accepted by at least two EGI sites. The Fermilab VO has been accepted by EGI, and most of the FIFE VOs are considered to be "sub-VOs" of the Fermilab VO, so if any of the others want to make their repositories available worldwide, they can be fast-tracked through the process when they request it in a GGUS ticket and say they are asking on behalf of the Fermilab VO.
- Dave Dykstra