Problem Statement
What are typical challenges when migrating virtual machines in large-scale systems and how can they be addressed?
Explanation
When migrating VMs at scale, challenges include compatibility of CPU features between source and target hosts, needing shared storage or having to transfer large amounts of memory state, network connectivity and IP continuity, performance hit and downtime, dependency on hypervisor versions, resource contention during migration and ensuring minimal service disruption. Mitigation includes live migration planning, using abstraction layers, homogeneous hardware clusters or CPU feature masking, shared storage or replication, and scheduling migration during low-utilisation windows. Mentioning real-world constraints and steps to address them enhances your answer.
