If you have an eye for detail, you may have noticed that the sizing guide for Discovery 20.02 (12) states that for produciton use, 64 GB RAM is the minimum for an appliance. This has increased from the Discovery 11.3 document recommends: 16 - 32 GB; For environments in which you discover storage, you should have more than 16GB RAM.
You may be wondering what has caused this increase - is there some specific feature or architecural change that now requires more RAM? Well, not really. If you just replace and existing 11.3 installation with 20.02 without changing usage profile, then you should see very similar RAM usage. Instead, it was felt that as time marches on more features are added that will steadily put introduce more memory pressure. Examples include:
Scanning large complex hosts or network devices with many interfaces
Complex patterns with large data sets to process
Large storage device discovery
Deep database discovery
Password store integration.
And RAM gets cheaper. Thus, if you are considering upgrading, it may be a good time to review your installation and performance profile and see if it will remain adequate for (say) the next 12 months or if you should consider some RAM upgrades. Note that some time ago I wrote about the importance of more RAM in the context of datastore performance.
Unfortunately, under Appliance Configuration, you will still see:
I logged this as defect DRUD1-29779, and should be updated in patch 2.