Adds documentation for reserved partition

doc/howtos.rst

@@ -199,4 +199,31 @@ Viking spectrometer
 
 * :doc:`Analysis of Viking spectrometer data <Analysis_of_Viking_spectrometer_data>`
 
+SLURM, sbatch, partition, reservation
+-------------------------------------
+
+Scripts launched by ``sbatch`` command can employ magic cookie with
+``#SBATCH`` to pass options SLURM, such as which partition to run on.
+To work, the magic cookie has to be at the beginning of the line.
+This means that:
+
+* to comment out a magic cookie, adding another "#" before it is sufficient
+* to comment a line to detail what the option does, it is best practice
+  to put the comment on the line before
+
+Reserved partition are of the form "upex_003333" where 3333 is the proposal
+number. To check what reserved partition are existing, their start and end
+date, one can ``ssh`` to ``max-display`` and use the command ``sview``.
+
+.. image:: sview.png
+
+To use a reserved partition with ``sbatch``, one can use the magic cookie
+
+``#SBATCH --reservation=upex_003333``
+
+instead of the usual
+
+``#SBATCH --partition=upex``
+
+
 .. _pyFAI: https://pyfai.readthedocs.io