Definition - What does Hot Add mean?
Hot add refers to the ability to dynamically add hardware, virtual or physical, to a running system without downtime.
Techopedia explains Hot Add
The evident benefit of a hot add is that system administrators can re-provision services without shutting down the systems. This may involve looking at some hardware or software requirements and the syntax for a particular administrative language.
In doing a hot add, system administrators need to determine whether the system has the resources to do this kind of provisioning on the fly. They may also have to check for things like server processor affinity for SQL, assess the schedulers and look at how a hot add will affect current operations.
The idea behind hot add is part of the overall scheme of virtualization — that hardware setups can be sliced and diced into more versatile virtual networks where one physical machine may represent five or six virtual machines, and where administrators can tinker with the allocation of processing power and memory to make operations more efficient.