Today's servers utilize controllers to connect storage drives, networks, and other technologies we used to call peripherals. These are often separate add-in cards utilizing PCI-e or other standards, though some server motherboards and chassis may offer built-in choices as well. Built-in controllers are convenient but may offer modest capacities and performance. They also are less readily upgraded to exploit technology improvements.
In this section, we will explore a number of choices for your Ceph servers' controllers.
HBA, synonymous with controller, describes a server component that attaches storage drives to the rest of the server. If that functionality is embedded in your motherboard versus being implemented with a discrete card, it is still an HBA. Carefully consider using embedded HBA's for Ceph data; their performance may be lackluster at best.
There are two main types of HBA: basic controllers, and ones that offer onboard RAID functionality....