ITPEC IP October 2022 Question 14

A backup machine kept ready and switched in immediately on failure — that is hot standby.

A standby (duplex) system pairs a production machine with a backup machine. In hot standby the backup is already running, with the same programs loaded, so when the production machine fails the system switches to it at once, with hardly any interruption. In cold standby the backup is kept stopped, or used for other work, and has to be started and prepared before it can take over.

Answer (c)

Why not others:

• •(a) — hardware, software and data provided to users over the Internet describe cloud computing, not a standby configuration
• •(b) — two sets running the same processing and cross-checking the results is a dual system
• •(d) — an operator starting up the backup after the failure is cold standby, which takes longer to switch over

Key rule: A dual system runs the same work on both machines and compares the results; a duplex system runs one machine and keeps the other on standby, hot (ready, switched in at once) or cold (started after the failure).

System Component · AI-written, may contain errors