Simplify the following text for a Grade 9 native English-speaking person.
Original: The little known failure mode is that delta logging relies on the original data being either in the old or the new state so as to enable backing out the logical change , yet few storage systems provide an atomic write semantic on a RAID disk .
Simplified: Logging relies on the original data being either in the old or the new state , though . This permits backing out the logical change , but few storage systems provide an atomic write semantic on a RAID disk .