Hi All,
I think the vital piece of information missing from this thread is that the Global Allocation Limit (GAL) for the DR instance needs to be 64GiB or the level of row data +20GiB, which ever is greater. The reason being that row data has to be in memory, as do the HANA services, column data is optional.
We monitor this important metric with Monitiq, as discussed in https://www.monitiq.com/monitoring-hana-replication-dont-forget-the-gal/
This combined with the setting to prevent pre-load of data, will provide space to house your non-prod environments using the unused resources on the second site. Remember not to exceed the 97% of physical memory when adding up the combined GAL's
Regards,
Robin Webster.