title: What is scratch space /filesystem in HPC
body: <p>I am studying about HPC applications and Parallel Filesystems. I came across the term scratch space AND scratch filesystem. </p>
  
  <p>I cannot visualize where this scratch space exists. Is it on the compute node as a mounted filesystem /scratch or on the main storage space.</p>
  
  <p>What are it's contents.</p>
  
  <p>Is scratch space independent on each compute node or, two or more nodes can share a single scratch space.</p>
  
  <p>So lets say I have a file 123.txt which I want to process parallelly. Will the scratch space contain the parts of this file or the whole file will be copied. </p>
  
  <p>I am confused and nowhere on google is there a clear description. Please point out to some.</p>
  
  <p>Thanks a Lot. </p>