Access files on JLab XrootD server

Here is an example of copying files to a location on the JLab EIC work disk that can then be accessed from anywhere using xrootd.

On a JLab ifarm machine, create a directory on the EIC work disk.

   ssh ifarm1901
   mkdir /work/eic3/users/davidl/2023.02.16.TriDAS_data

Copy files to the directory. Here, I do this from the group account streamdaq on clondaq5

   scp /data/tridas/EIC_3x3_R00000235_F00000004.pt davidl@ifarm1901:/work/eic3/users/davidl/2023.02.16.TriDAS_data

You should now be able to access the files using an xrootd client on your local computer.

If you have 'MacOS and have homebrew installed, then just install the xrootd package:

   brew install xrootd

This will allow you to run the xrdfs, xrdcp, ... programs directly. For example, you can list the contents of a directory with something like the following. The key info is to use dtn-eic.jlab.org as the host and the path will be the same as on the CUE.

   xrdfs dtn-eic.jlab.org ls /work/eic3/users/davidl/2023.02.16.TriDAS_data
     /work/eic3/users/davidl/2023.02.16.TriDAS_data/EIC_3x3_R00000235_F00000004.pt

If you have issues with that or want to use another platform, then you can always use docker. Here is how I do it with a docker container:

   docker run --rm -it lukasheinrich/xrootdclient xrdfs dtn-eic.jlab.org ls /work/eic3/users/davidl/2023.02.16.TriDAS_data
     /work/eic3/users/davidl/2023.02.16.TriDAS_data/EIC_3x3_R00000235_F00000004.pt

To copy a file to your local machine, use the xrdcp command. Again, using docker

   # Use the "-v ${PWD}:/work" option to bind the current directory
   # on your local machine to a directory named "/work" inside the
   # container. This lets the you copy to the host file system rather
   # than the temporary one docker creates for the container.
   docker run --rm -it -v ${PWD}:/work lukasheinrich/xrootdclient xrdcp root://dtn-eic.jlab.org//work/eic3/users/davidl/2023.02.16.TriDAS_data/EIC_3x3_R00000235_F00000004.pt /work