In distributed storage, which statement about scalability is true?

• A. It uses vertical scaling only.
• B. Expands by adding nodes to increase both computing capability and storage space.
• C. Cannot support elastic EC for data redundancy protection.
• D. Cannot pool storage resources.

Answer: (B)

Scalability in distributed storage is achieved through horizontal scaling—adding more nodes to the cluster to expand both storage capacity and computing power. As you bring in additional machines, their resources are pooled so the system presents a single, larger storage pool and can handle more I/O and processing tasks. This growth also enables elastic data protection, such as adaptive erasure coding, which adjusts redundancy as the cluster changes, improving efficiency. The other statements don’t fit because vertical scaling alone doesn’t utilize the distributed nature, resources are indeed pooled across nodes, and elastic erasure coding is supported in capable distributed storage systems.