I'm only talking about doing a sync that purely adds data to the parity and does not remove any. So lets say I have built parity for 10 files, then I add another 10 files and delete one, the diff would show 10 additions and 1 removal. A sync currently would update parity to match those 19 files and I could no longer recover the deleted files. What I'm suggesting is a partial sync where I want to ignore deletions. So update the parity for the new 10 files, but keep the existing parity for the 1 missing...
Would it be technically possible to selectively sync contents rather than syncing all changes? Im thinking of scenarios such as sync all additions and modifications but dont sync deletes. Or sync this list of files that I got from the diff. I understand if its not possible due to the way parity is computed (I dont know enough details), but if it is technically possible it would be a great feature. I could sync every day without worrying about drive failure syncing deletes for example, until I can...