Azure VMSS Zonal Expansion empowers users to transition their regionally configured virtual machines (VMs) into a zonal configuration across Azure availability zones. This translates to an impressive boost in business continuity, resilience, and an increase in your availability Service Level Agreement (SLA) from 99.95% to a promising 99.99%.
Azure availability zones are distinct data centers within a region, each having unique power, cooling, and network systems. By distributing VMs across multiple such zones, Azure is able to commit to higher SLA guarantees. This distribution strategy is called a zonal redundant configuration. In the past, moving VMs from non-zonal to zonal configurations was labor-intensive and caused significant application downtime. This new feature make this migration straightforward, minimizing disruptions.
Read more in the blog.