====== Storage Guidelines HPC ======
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===== Storage Types =====

| Storage type | Where/Mount | Mount type | Purpose | Quota | Capacity |
| HOME     | <code>/[homes|homes2]/[your_faculty|extern]/[username]</code> | network | Program application data; only small files (very precious data) | <code>~ 2.5 GiB</code> | - |
| WORK     | <code>/work/[username]</code> | network | **Permanent** data storage; NO scratch files| NO | - |
| BeeGFS  | <code>/fast/[your_directories]</code> | network | **Scratch** Storage of **(very) large** files | NO  | - |
| Local Scratch | For batch jobs: <code>$TMPDIR</code> or optionally: <code>/scratch/[your_directories]</code> | node-local FS \\ (shared by all jobs running on node) | Intermediary scratch storage for **small and moderate-large** files | NO | <code>~ 200 - 500 GiB</code> |
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===== Recommendations =====

  * ''BeeGFS'' (parallel distributed file system): preferred for **large scratch files (starting from files sizes of a few hundreds of MiB) AND (semi-)permanent storage of scratch files**
  * ''Node-local Scratch'': **fast, local FS storage** for small to intermediary sized scratch files up to a size of few GiBs; big amounts of small scratch files should be written here (BeeGFS shows poor performance for files with sizes smaller than a few hundreds of MiB)
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===== General Warning =====

  * **Please ensure, that your programs DO NOT write huge amounts of scratch files or data to your WORK (as this will block other users from getting their work done).**
  * **Please avoid (permanent) storage of un-needed scratch files and do not copy them to your WORK.**
  * **Please write your scratch files to node-local or BeeGFS (depends on size of the files; see section "Recommendations"). If needed, copy the program's checkpoint files from node-local scratch to BeeGFS.**

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date of revision: 03-24-2020 © kraus
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