I've got a question regarding how extents in scale out repository function. Say, scale out repositories are setup for performance i.e. incremental files and full backup files will be stored on different extents. So, in case of reverse incremental backup what's the process, how does the whole operation happens? As in does proxy liaises with both repositories for injecting the latest backup in the vbk file and then reading and writing the previous restore point on to other extent. Or during this operation extents communicate with each other to manage the whole reverse incremental operation?
I just want to understand how the communication flows.