Changing disk library for primary storage policy copy

@drPhil , you pretty much answered it yourself: if you want to fully move everything over, create a Deduplicated aux copy, let it complete, then promote it (you can delete the original Primary if you wish after, assuming you need the space/library for something else or just let it age on its own time).

You CAN add another library to the Data Paths, disable the old one for write, seal the store, then wait for those older baseline jobs to age off, but that will take a while depending on your retention.

Thanks, @Mike Struening. I have just one additional question. Then, after promoting the newly created secondary copy, is it posible after some time to revert changes and make old primary copy back to be the primary one?

You could……though that would assume you are continuously treating the old Primary/new aux as a true Aux copy and keeping it up to date.  that way, when you flip it back, there’s little to no catch up required.