Merge pull request PSU-ICDS#209 from PSU-ICDS/staging

Update Hardware Specifications

Author: CarrieBrown

docs/getting-started/tips-for-beginners.md

@@ -38,7 +38,7 @@ do more than use the Portal needs to learn.
 
 To learn more about Linux, we recommend the following resources:
 
- - [Unix tutorial]: https://www.tutorialspoint.com/unix/unix_tutorial.pdf
+ - [Unix tutorial]: (https://www.tutorialspoint.com/unix/unix_tutorial.pdf)
  - [Effective Computation in Physics - Chapter One](https://www.oreilly.com/library/view/effective-computation-in/9781491901564/?sso_link=yes&sso_link_from=pennsylvania-state-university)
  - [Introduction to Using the Shell in an HPC Context by HPC Carpentry](https://www.hpc-carpentry.org/hpc-shell/) which can be followed after [logging onto Roar](connecting.md/#two-ways-to-access) and [accessing the command line](../running-jobs/portal.md#command-line-access).
 

docs/system/compute-hardware.md

@@ -21,3 +21,6 @@ The different types of nodes available on Roar are:
 | High Memory <br> (20 GB/core) | 25 | 48 | 1024 | Gold 6342 | icelake | Infiniband |
 | Interactive | 16 | 28 | 512 | E5-2680v4 <br> + P100 GPU | broadwell| Infiniband <br> Ethernet|
 
+Note: While cluster nodes are configured with the memory described above, some of the memory
+is reserved for the operating system and system processes, so not all memory is available for
+user jobs.  We normally reserve less than 10GB of memory for the operating system.