Home > Data Protection > PowerProtect DD Series Appliances > PowerProtect DD Data Invulnerability Architecture: Enhancing Data Integrity and Recoverability > Continuous fault detection and healing
Regardless of the software safeguards in place, it is the nature of computing hardware to have occasional faults. Most visibly in a storage system, disk drives can fail, but other more localized or transient faults also occur. An individual disk block might be unreadable, or a bit flip error could occur on the storage interconnect or internal system bus. For this reason, DD OS builds in extra levels of data protection to immediately detect faults and recover from them to ensure successful data restore operations.
The following figure illustrates how the system protects against storage system faults. It periodically rechecks the integrity of the RAID stripes and the container log, and uses the redundancy of the RAID system to heal any faults. During every read, data integrity is reverified, and any errors are immediately healed.