> --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