Theoretically, the cloud seems tailor-made for ensuring high availability (HA) and disaster recovery (DR) solutions in mission critical SQL Server deployments. Azure, AWS, and Google have distributed, state-of-the-art data centers throughout the world. They offer a variety of SLAs that can guarantee virtual machine (VM) availability levels of 99.95% and higher.
But deploying SQL Server for HA or DR has always posed a challenge that goes beyond geographic dispersion of data centers and deep levels of hardware redundancy. Configuring your SQL Server for HA or DR involves building a Windows Server Failover Cluster (WSFC) that ensures not only the availability of different machines running SQL Server itself but also — and most importantly — the availability of storage holding the data in which SQL Server is interacting.
