Making backups more granular means you remove sets of backups (or you collapse incremental backups). If a new backup causes corruption to back-propogate then it's not a backup.
What does this mean? How do you store an arbitrarily long sequence of changes on a medium of fixed size without overwriting? Eventually you will run out of disk and old data will have to be overwritten, which might have contained the only good copy of the corrupted file.
> If a new backup causes corruption to back-propogate then it's not a backup
I'll go further and say that even backup that forward-propagates corruption is not backup either - all the incremental backups from the moment of corruption are worthless. Bottomline: if your backup cannot be restored with integrity intact - it's not backup!
