Version 2015-07-08 adds support for incremental snapshots for page blobs. Incremental snapshots are a cost-effective way to back up virtual machine disks if you wish to implement your own backup solution.
To support incremental snapshots, the Get Page Ranges operation now exposes the
prevsnapshot parameter, which takes a
DateTime value indicating an existing snapshot. Calling Get Page Ranges with the
prevsnapshot parameter returns pages that have been updated or cleared since the snapshot specified by
prevsnapshot was taken. You can then copy the pages that are returned to a backup page blob in another storage account, using Put Page.