We have a SOBR with some extents that all match up to individual volumes on some Cisco storage servers. We are getting low on space across all of the extents, so we have purchased another Cisco storage server to add to the SOBR. My question is about our active backup jobs that go to this SOBR. I know that any newly backed up VMs would choose the new empty extents we add to the SOBR, but I believe that all existing backup chains would continue to write to the extents where they currently reside (which are getting full). This is because we are using the "Data Locality" policy. We do this because we use the per-VM backup chains and utilize the ReFS space savings, so we want an entire backup chain to be on the same extent.
What would be the best way to get some of our already backed up VMs to start writing to the new empty extents? The description of the data locality policy says that "...however, the next full backup can be created on another extent". If I add some empty extents to the SOBR, does this mean that the next time it takes full backups it will choose to write to the new extents since it sees there is free space and it generally tries to balance it all out?
If not and I am misunderstanding, is there something else we can do to migrate backup files from the current almost-full extent over to the new extents so that we do not run out of space?