.. _best_practices:

==============
Best Practices
==============

.. contents:: In this section:
   :local:
   :depth: 2

This section gathers essential recommendations for the responsible and efficient use of GridUnesp resources. Following these practices contributes to the proper operation of the cluster for all users.

Sharing Access
==============

.. warning::
   **Never share your password with third parties.**

As a security measure, your account is personal and non-transferable. Members of the same project, advisors, or even the GridUnesp team **must not** have access to your password.

**Risks of sharing:**

- Accidental deletion of files (cannot be undone)
- Unauthorized modification of data
- Submission of jobs in your name
- Compromise of cluster security

**How to collaborate safely:**

If you need to share files with other users, use access permissions:

.. code-block:: bash
   :caption: Adjusting permissions for collaboration

   # Grant read permission to the group
   chmod g+r shared_file.dat

   # Grant read/execute permission to a directory
   chmod g+rx shared_directory/

   # Remove permissions for others (safe default)
   chmod o-rwx shared_directory/

.. tip::
   For collaboration on projects, ask your coordinator about creating group directories with appropriate permissions.

Requesting Support
==================

Before requesting support, check the :ref:`faq` section - most questions have already been answered.

**When sending an e-mail to ``support.ncc@unesp.br``, include:**

1. **A clear description of the problem**
2. **The location of the submission script** (full path: ``/home/$USER/path/to/file/script.sh``)
3. **The location of the input files** (if applicable)
4. **Log files** (slurm-JOBID.out)
5. **The command used to submit the job**
6. **The number(s) of the job(s) in question** (if any)

.. important::
   The more information you provide, the faster and more accurate the support team's response will be.

.. _data_maintenance:

Data Maintenance
================

Backup Policy
-------------

.. danger::
   **GridUnesp does NOT have an automatic backup system.**

In case of an unrecoverable failure of the storage system, **all data will be lost with no possibility of recovery**.

**Recommendations:**

1. Transfer important results to your local computer
2. Keep copies in at least two different locations
3. Do not use the cluster as the only copy of critical data
4. Keep only the files needed for processing on the cluster

Disk Space Management
---------------------

Since resources are shared, unnecessary accumulation of data harms all users.

**Check your space usage:**

.. code-block:: bash
   :caption: Analyzing usage in /home/

   du -scm $HOME/$USER/* | sort -nr | head -20

**Cleanup in /home/:**

.. code-block:: bash
   :caption: Removing unnecessary files

   # Remove specific files
   rm slurm-*.out obsolete_program

   # Remove directories (be careful!)
   rm -rf old_results/ temporary_tests/

.. attention::
   **The /store/ partition**

   Jobs that use multiple nodes or have the variables ``SHARED_FS="true"`` or ``LARGE_FILES="true"`` write to ``/store/``. This partition also requires periodic cleanup:

   .. code-block:: bash
      :caption: Checking space in /store/

      du -scm /store/$USER/* | sort -nr | head -20

      # Remove directories of old jobs
      rm -rf /store/$USER/2835861 /store/$USER/2835862

      # OR remove everything (only if you are sure!)
      # rm -rf /store/$USER/*

.. danger::
   When storage reaches 100% usage, **the entire system is compromised**, affecting the jobs of all users.

Processing on the Access Server
===============================

.. important::
   **The access.grid.unesp.br server must NOT be used to run jobs.**

Functions of the **access** server:

- Entry point to your account
- Preparation of scripts and files
- Submission of jobs with ``sbatch``
- Light pre/post-processing tasks (fast and low memory)

**Permitted exceptions:**

- Editing small files
- Quick compilations
- Organizing directories
- Very brief tests

.. danger::
   The GridUnesp team monitors the use of the **access** server. Heavy processing will be **immediately canceled** so as not to harm other users.

Best Practices Summary
======================

✅ **Always:**

- Use ``sbatch`` to submit jobs to the processing nodes
- Keep backups of important data
- Clean up temporary files regularly
- Include complete information when requesting support

❌ **Never:**

- Share your password
- Run jobs on the **access** server
- Use the cluster as your only storage location
- Accumulate unnecessary data

.. seealso::

   - :ref:`detailed_storage_info` - Details about partitions
   - :ref:`running_simulations` - How to submit jobs correctly
   - :ref:`job_nanny_parameters` - Settings for /store/ and /tmp/