US Patent 6892221 Data backup

A system, signal and method for data backup. The method, comprising the steps of: identifying at least one data increment which was previously provided to a subscriber server or generated by a subscriber server and which is to be backed up; checking at least one service provider access server to determine if it has a copy of at least a portion of the identified data increment or can regenerate or replicate at least a portion of the identified data increment; and backing up the data increment using the copy or regenerated or replicated portion from the access server if it is found and otherwise using a copy sent from the subscriber server after the checking step.