OS hardening includes reducing the operating system's attack surface by disabling services that are not required. BIOS passwords and hardware deactivation are firmware or physical hardening measures.

Because of the varying sizes/types of HDs in the question and that is requests end users to see ALL the drives within JBOD would be a better selection than RAID. With a RAID it would appear as one logical unit and the varying sizes would have a limit of the smaller disks used.
https://www.techtarget.com/searchstorage/definition/JBOD

A warm site is a type of facility an organization uses to recover its technology infrastructure when its primary data center goes down. A warm site features an equipped data center but no customer data.
The warm site has some or all of the IT equipment found in a typical primary data center, such as software and hardware. After a disaster at the primary site, an organization will introduce customer data and may install additional equipment at the warm site.