install.py should recommend different settings for minimal memory instances, if possible

[mmguero]

@mmguero cloned issue idaholab/Malcolm#85 on 2022-03-28:

Moved from #204 by @RafnexJr.

When following the default recommendation of the memory allocation the setup script provides and the system has no swap configured Opensearch repeatedly crashed because it can't allocate enough memory. Problems occured when the server has below 12 GB memory and now swap configured, it happend on Ubuntu, Debian and OpenSUSE.

To reproduce

Steps to reproduce the behavior:

• Server with 8GB memory and no swap

• Install according to documentation

• Start Malcolm with the script

Expected behavior

The script should recommend less memory for Opensearch and Logstash when the system has below 12 GB memory and no swap.

Any helpful log output or screenshots

The following output is shown (not exactly copied)

OpenSearch exited with code 137