Azure Virtual Machines—Managed Disks
Managed Disks will provide persistent, secured disk storage for Azure Virtual Machines. It'll ensure that the disks of different virtual machines in an availability set are created on physically separate stamps of storage. It'll also offer the ability to control access to the disk through Role-Based Access Control—the same security mechanism Azure will use to grant access to other resources. The underlying VHDs for managed disks won't be exposed directly to users, mitigating the risk of users accessing via the storage account directly.
Managed Disks will simplify managing storage and capacity planning in Virtual Machines. It'll increase resiliency and minimize mistakes by abstracting the underlying architecture from the user. It will also honor fault domains within an availability set. For additional physical redundancy, it'll deploy disks into storage accounts in the same fault domain as the virtual machines.
Read more about Managed Disks in this blog post.