Which of the following concepts allows an organization to group large numbers of servers together in order to deliver a common service?

A.
Clustering

B.
RAID

C.
Backup Redundancy

D.
Cold site

Explanation:
Anytime you connect multiple computers to work/act together as a single server, it is known as clustering. Clustered systems utilize parallel processing (improving
performance and availability) and add redundancy (but also add costs).
Clustering is done whenever you connect multiple computers to work and act together as a single server. It is meant to utilize parallel processing and can also add
to redundancy.
Incorrect Answers:
B: RAID, or redundant array of independent disks (RAID). RAID allows your existing servers to have more than one hard drive so that if the main hard drive fails,
the system keeps functioning.
C: Backup redundancy is a disaster recovery measure.
D: A cold site is a facility that isn’t immediately ready to use. The organization using it must bring along its equipment and network. A cold site may provide network
capability, but this isn’t usually the case; the site provides a place for operations to resume, but it doesn’t provide the infrastructure to support those operations. It is
one of the disaster recovery measures.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, Sixth Edition, Sybex, Indianapolis, 2014, pp 234-235, 444