Which type of disk drive redundancy uses separate controller cards for each disk and duplicates the contents of one disk to a second disk?

Correct option is A

1. Concept of Disk Mirroring:
· Disk mirroring is a RAID Level 1 technique.
· It involves duplicating the contents of one disk onto another disk in real time.
· Each disk operates with its own controller, which ensures data redundancy and protection against disk failures.
2. Separate Controller Cards:
· Having separate controllers for each disk ensures there is no single point of failure in the storage subsystem.
· This approach is common in high-reliability systems.
Important Key Points:
1. Disk Mirroring:
· Ensures high availability by creating an exact copy of the data.
· It is widely used in enterprise environments for critical data protection.
· Commonly implemented as RAID 1.
2. Drive Striping:
· Improves performance by spreading data across multiple disks.
· Lacks redundancy and is unsuitable for critical data storage.
Knowledge Booster:
1. Other RAID Levels:
· RAID 0: Striping, no redundancy, improved performance.
· RAID 1: Mirroring, redundancy but no performance improvement.
· RAID 5: Striping with parity, balanced performance, and redundancy.
· RAID 10: Combines mirroring and striping, high performance, and redundancy.
2. Controller Cards:
· Single Controller: A single point of failure, less reliable.
· Dual Controllers: Adds fault tolerance, ensuring system continuity even if one controller fails.