Which technology best supports 24/7 availability for critical systems?

Mirroring technology is specifically designed to ensure high availability and resilience for critical systems, making it the best choice for supporting 24/7 availability. This approach involves creating real-time copies of data across multiple locations or systems. In the event of a system failure or outage, the mirrored system can immediately take over without significant downtime, ensuring that services remain consistently available.

Using mirroring allows for synchronization of data between the primary and secondary systems, which keeps the information current. This capability is crucial for environments that require uninterrupted access, such as those handling transactions or sensitive data.

The other options, while they have their own benefits, do not provide the immediate availability that mirroring does. Daily backups may help in recovering data in the event of loss but do not ensure that systems are continuously available. Offsite storage protects data from physical disasters, but it also does not support live operations. Periodic testing is important for validating disaster recovery plans but does not contribute to the continuous operation of systems. In contrast, mirroring excels at maintaining real-time access to critical systems, making it the best option for supporting 24/7 availability.