Several legacy VMs use unmanaged disks stored in Standard_LRS storage accounts and are hitting storage account IOPS limits. A new database workload requires predictable high performance on data disks. You want to eliminate storage account throttling risk and meet the performance needs. What should you do?

Migrating to managed disks is crucial because managed disks abstract away the storage accounts, eliminating the IOPS limits associated with unmanaged disks in a single storage account. This directly addresses the throttling risk. For the new database workload requiring predictable high performance, using Premium SSD managed disks is the correct choice. Premium SSDs offer guaranteed IOPS and throughput, and their performance scales with disk size, allowing you to provision disks specifically to meet the database's demands. Moving unmanaged disks to PremiumLRS storage accounts might offer better performance than StandardLRS, but it doesn't eliminate the fundamental per-storage-account IOPS limits inherent to unmanaged disks, which can still lead to throttling. Enabling blob caching is for read performance and doesn't address the underlying IOPS limits of the storage account or the write performance needs of a database. Adding more unmanaged data disks to the same storage account will exacerbate the problem, as the storage account itself is the bottleneck.