Good to know: What is hot swapping?

05.03.2020

Anyone who has already dealt intensively with individual Mini-PC components such as SSDs or the term RAID will certainly have come across the term “hot swapping”. In this article, we explain what this is and what advantages hot swapping offers in practice.

A hot swap is basically the replacement of PC peripherals while the system is running. The components to be replaced are not connected to the operating system or other software. This means that neither the power supply is interrupted nor the system restarted.

Assuming a fan is defective while the Mini-PC is running, the damaged fan can be easily replaced with a new one thanks to hot swapping. Other components, such as PCIe or SATA drives in a RAID array, can also be swapped using hot swap.

Basis for hot swapping

For a component to be replaced using hot swapping, the associated plug connection must meet certain criteria. The plug contacts must have a leading design, which means that the contacts are connected and disconnected in a defined sequence, usually in three or more stages. This is realized by a common housing in which the contacts are positioned further forward and further back. The most common systems with leading plug contacts are SATA and USB (see Fig. 1).

The user should also ensure that the plugs are plugged in and unplugged as straight and slowly as possible.

Good to know: What is USB?

What are the advantages of hot swapping?

As already mentioned at the beginning, the advantage of hot swapping is that systems do not have to be restarted and there is no need to interrupt operations to replace broken components. Particularly in the area of servers or in industry, where PCs have to be in use 24/7, the rapid replacement of components using hot swap offers a decisive advantage, as even the slightest interruption to operation can mean an enormous loss.

Variants of hot swapping

Hot Add: Describes the addition of new components that work without configuration in the running system.
Hot Plug: The addition and removal of components during operation as long as no software accesses them, also known as plug and play .
Hot switch: Switching between components, for example to a redundant power supply unit.