In SAS architecture, what is the role of expander devices?

• A. They connect multiple devices to the host adapter.
• B. They convert SAS to SATA.
• C. They provide data encryption.
• D. They manage power distribution.

Answer: (A)

Expander devices in SAS act like switches inside a SAS fabric, allowing one host adapter to communicate with many SAS and SATA devices. They take the single or few ports from the host and fan out to a large number of drives, routing frames and managing addresses so each device can be reached efficiently. This scalable topology is what enables attaching multiple disks or enclosures behind one controller. They don’t convert SAS to SATA, provide encryption, or handle power distribution—that kind of functionality is outside the expander’s role and handled by other components.