In migration strategy, what is the concept of a "pilot light"?

• A. Run a full production environment in the cloud before migrating on-prem systems.
• B. Run a small, always-on portion of the environment in the cloud to speed up full production deployment later.
• C. Migrate only the data and not the applications.
• D. Use a one-time data snapshot for cutover.

Answer: (B)

In a pilot light approach, you keep a small, always-on portion of the environment in the cloud that runs the essential components and data. This baseline is continuously kept up to date and ready, so when you’re ready to cut over, you can quickly scale up to full production in the cloud. The idea is to minimize upfront infrastructure while still having a ready-to-go footprint that speeds deployment and reduces downtime during migration.

This works well because keeping a minimal cloud footprint with automated replication of critical data means you don’t start from scratch at cutover, and you can ramp up to full capacity more quickly and with less risk.

Rationale for the other options: starting with a full production cloud environment defeats the cost-saving and speed goals of pilot light, because you’ve already moved everything before the migration. Migrating only data ignores the need to run and test the application and services in the cloud. A one-time data snapshot for cutover lacks the continuously running, minimal cloud environment that facilitates rapid and reliable transition.