.. _tutorials-onboarding-m2-quiz:

Quiz
====

Use this self-check to test your understanding of data handling, paths, and storage quotas on the CoSTAR cluster.


These questions are browser-side self-checks. They are not formally graded and can be retaken as many times as needed.

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   ### Which of the following statements about the CoSTAR storage systems are TRUE?

   Select all that apply:

   - [x] The personal home directory (``/users/<username>``) has a strict 30 GB storage quota.
       > Correct. Home directories are small and meant exclusively for code, configuration files, and basic environments.
   - [x] The WekaFS parallel storage workspace is built for ultra-fast performance but is not backed up.
       > Correct. High-performance filesystems bypass heavy backup overhead to maximize raw file I/O speed.
   - [x] There is no rigid, restrictive user-specific quota on the shared parallel scratch workspace, making it ideal for massive datasets.
       > Correct. The shared scratch space allows flexibility for large training sets, but it is a shared resource that must be managed responsibly.
   - [ ] The parallel scratch filesystem is fully backed up nightly by system administration.
       > Incorrect. Scratch storage is temporary and never backed up. You are responsible for preserving critical data.
   - [ ] Running heavy AI training loops directly out of your home directory is recommended for stability.
       > Incorrect. Home storage lacks the parallel throughput of WekaFS; doing this will bottle-neck your GPUs and quickly exhaust your 30 GB quota.

   ### What is the primary purpose of the high-performance parallel scratch workspace on CoSTAR?

   1. [x] Running active compute jobs and handling large, high-throughput files during execution.
       > Correct. The parallel NVMe flash fabric is optimized to stream massive datasets directly to training models without I/O choke points.
   1. [ ] Storing personal scripts, repositories, and local environment files permanently.
       > Incorrect. Long-term static files belong in your home space or project environments.
   1. [ ] Long-term archival and backup of historical research data.
       > Incorrect. Scratch directories are unbacked and subject to periodic clean-up cycles.
   1. [ ] Serving as a public file-sharing workspace for collaborators outside the university network.
       > Incorrect. Access is strictly confined within the cluster security perimeter.

   ### Which command-line tool is highly recommended for transferring large project directories or resuming interrupted file transfers to CoSTAR?

   1. [x] ``rsync``
       > Correct. ``rsync`` is highly efficient because it compares file deltas and can securely resume an interrupted transfer right where it left off.
   1. [ ] ``scp``
       > Incorrect. While useful for quick single-file drops, ``scp`` is inefficient for multi-gigabyte datasets and cannot cleanly resume broken transfers.
   1. [ ] ``ftp``
       > Incorrect. Plain FTP is an insecure, unencrypted legacy protocol and is completely blocked on the gateway.
   1. [ ] ``cp``
       > Incorrect. The ``cp`` command is exclusively for duplicating files locally within the cluster filesystem, not over the network.

   ### What is the storage quota for a user's personal home directory space on the CoSTAR login subsystem?

   1. [x] 30 GB
       > Correct. Your personal home environment has a hard limit of 30 GB to preserve system stability on the head node.
   1. [ ] 200 GB
       > Incorrect. This was a limit on legacy configurations; CoSTAR utilizes a streamlined 30 GB layout for configuration and code.
   1. [ ] 750 TB
       > Incorrect. 750 TB represents the total pooled capacity of the flash-backed WekaFS array, not individual home allocations.
   1. [ ] Unlimited
       > Incorrect. Cluster resources are finite and governed to ensure high availability for all users.

   ### Which of the following are considered best practices for managing storage on CoSTAR?

   Select all that apply:

   - [x] Regularly synchronizing important source files, models, and results to external platforms like GitLab or Hugging Face.
       > Correct. Because cluster volumes are not long-term archives, pushing critical assets to secure remotes prevents data loss.
   - [x] Cleaning up temporary files and clearing out old checkpoint runs from the parallel workspace as soon as a job series finishes.
       > Correct. Keeping the parallel volume clear helps maintain top speed and ensures ample room for other active research teams.
   - [ ] Running all computational tasks out of your home directory to ensure they remain safe from cleanup loops.
       > Incorrect. Tasks should always be executed within the parallel workspace to leverage proper storage bandwidth.
   - [ ] Storing all model training data inside scratch directories indefinitely so you never have to re-download them.
       > Incorrect. Treat scratch purely as an active runtime workspace. Data left idle can be flagged or automatically purged during maintenance windows.