Final answer:
To determine Host Memory Health, the two key metrics are Available memory and swap usage, which are crucial indicators of a system's memory performance and overall health.
Step-by-step explanation:
The two metrics used to determine Host Memory Health are a) Available memory and swap usage. Available memory refers to the amount of memory that is currently not being used and is readily available for new processes. Swap usage indicates the amount of disk space being used to supplement physical memory by temporarily storing data that is not actively being used. These metrics are crucial for assessing the health of a system, as insufficient memory can lead to swapping, which could degrade system performance.