In a dual-redundant mission computer architecture, which statement about hot spares is true?

In a dual-redundant mission computer architecture, which statement about hot spares is true?

• A. Hot spares are active and ready to take over instantly.
• B. Warm spares are powered but idle.
• C. Cold spares are powered on and used immediately after a fault.
• D. Spares are unnecessary in this architecture.

Answer: (A)

In a dual-redundant mission computer, hot spares are powered and actively running, ready to take over immediately if the active channel fails. This setup minimizes downtime because there’s no boot or initialization delay—the spare is already performing and can switch over instantly when a fault is detected. A description of warm spares would be that they’re powered but in standby, not actively processing, so they can’t guarantee instant takeover. Cold spares are powered off and would require power-up and system initialization after a fault, causing longer downtime. The idea that spares aren’t needed contradicts the purpose of redundancy. So, hot spares being active and ready to take over instantly is the true characterization.

In a dual-redundant mission computer, hot spares are powered and actively running, ready to take over immediately if the active channel fails. This setup minimizes downtime because there’s no boot or initialization delay—the spare is already performing and can switch over instantly when a fault is detected. A description of warm spares would be that they’re powered but in standby, not actively processing, so they can’t guarantee instant takeover. Cold spares are powered off and would require power-up and system initialization after a fault, causing longer downtime. The idea that spares aren’t needed contradicts the purpose of redundancy. So, hot spares being active and ready to take over instantly is the true characterization.