The Design and Organization of Data Centers/Redundancy

Everything will eventually fail. Redundancy allows you to minimize the damage of a system failure.

Failure characteristics

Planned vs. unplanned

Total vs. partial

Frequency of failure

Length of partial failure or outage

Types of redundancy

Structure

Ladder

Mesh

N+1

Implementation

Active/active

Active/passive

Human Factors

Notification

Unattended problem resolution

Documentation and problem clarity

Allowance for no-impact maintenance