add kronos docs

sphinx_docs/source/olcf-kronos.rst

@@ -0,0 +1,48 @@
+Archiving Data on Kronos
+========================
+
+`Kronos <https://docs.olcf.ornl.gov/data/#kronos-nearline-archival-storage-system>`_
+is the mass storage system at OLCF.  Each user has a directory of the form:
+
+.. code:: bash
+
+   /nl/kronos/olcf/<projectID>/users/<userID>
+
+and data can be transferred there using standard Unix commands.
+
+.. note::
+
+   You need to be logged into ``dtn.olcf.ornl.gov`` to access kronos.  It is
+   not visible directly from Frontier or Andes.
+
+A submission / shell script pair that automates the transfer of data is available in
+`workflow/job_scripts/hpss <https://github.com/AMReX-Astro/workflow/tree/main/job_scripts/hpss>`_ as:
+
+* ``olcf_kronos.submit`` : the slurm submission script
+* ``kronos_process.sh`` : a BASH script that finds output and automates the archiving.
+
+You submit the job from the directory containing the plotfiles you wish to archive.
+It will then:
+
+* tar up the diagnostic files, inputs, and other metadata into a file with the
+  date-stamp in the file name and copy that to kronos
+
+* find all of the plotfiles and tar them directly to kronos.  If the tar is successful,
+  it will move the plotfile into a ``plotfiles/`` subdirectory and add a ``.processed``
+  file so the script knows it was archived already.
+
+* find the checkpoint files matching a pattern (currently defaults to every 5000 steps)
+  and archive those in the same fashion, moving them to a ``checkfiles/`` subdirectory
+  once archived.
+
+* loop, looking for new output files
+
+By default, it will not transfer the last file, in case it is actively being written to.
+
+.. tip::
+
+   The ``olcf_kronos_once.submit`` can be used to just transfer without the loop
+   waiting for new files.
+
+
+

sphinx_docs/source/olcf.rst

@@ -9,4 +9,5 @@ Working at OLCF
    olcf-compilers
    olcf-workflow
    olcf-jupyter
+   olcf-kronos
    olcf-andes