Explanation/Reference:
Create a replication session
Ensure that you have first created relevant replication interfaces and connections, and then you need the name, pool, storage provisioning, and tiering policy you want to use for the destination storage resource.
The system will automatically created a destination storage resource as part of this process.
References: https://www.emc.com/dam/uwaem/documentation/unity-p-replication-config.pdf (page 23)

Explanation
Note: Boot counters are a troubleshooting mechanism that is designed into the Unity architecture to help pinpoint the specific cause of software or hardware events during the boot sequence. If the Unity system detects a problem with software or hardware components, its corresponding Boot Counter is incremented. If a counter reaches a predefined threshold, the SP boots into Service Mode during its next boot cycle.
References: https://www.emc.com/collateral/TechnicalDocument/docu69328.pdf (page 12)