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Hi Chris, > --basedir/mps.basedir option is completely ignored in the mps_PreStage > code and fixed it) but I cannot work out how one is suppose to integrate > it with the xrootd/olbd system. Just send me the updated file and I'll integrate the changes. > mps_prep seems to take completely different arguments to mps_stage so we > cannot just drop that in as a replacement, more seriously it returns as > soon as the file is placed in the stage queue not when the file is on > disk. Do we need to write yet another wrapper script to translate the > options and hold on until the file has appeared. Yes, you will since xrootd relies on the behaviour that mps_prep will return as soon as the request is in the queue. The actual queing for file appearance is handled internally in xrootd. If mps_prep were to wait, xrootd would be seriously impacted. So, don't do that! > The MPS documentation suggest that the olbd interacts directly with the > stage queue but doesn't give any details. The olbd uses the staging system to handle the "prepare" request which allows one to pre-stage file before they actually get used. See the "olb.prep" directive. Andy