A joint effort by immersion cooling firm Iceotope and Meta, the parent company of Facebook, found cooling hard drives with a dielectric liquid is safe and a more effective means of cooling than using fans.
Hyperscalers like Meta deploy thousands of HDDs in their data centers, and while the heat given off on an individual basis is tiny, it adds up, especially since the drives are in constant use and are close together. The drives are stored in server racks that hold nothing but dozens of hard drives and are referred to as a JBOD (Just a Bunch Of Disks).
A JBOD can overheat without cooling, which up to now has been done with fans, but some drives were further away from fans than others, causing uneven cooling.
Source:: Network World – Data Center