I do daily file system backups of all critical data for my websites. I'm wanting to optimise the backup process by limiting the files that get backed up to only those absolutely necessary to restore the site back to a working state. To minimise space, I exclude the internal_data/attachments folder from the daily backup and instead use rsync to mirror that directory to another machine. However, there are other folders in the internal_data directory which I'm not sure if the system will be able to recover if I exclude them from the backups? image_cache page_cache sitemaps temp templates Is it safe to exclude these folders?