During writing of the data checksums are created and stored. When read again, a new checksum is created and compared to the initial checksum. If incorrect, a checksum is created from another replica of the same data. After succesful comparison this replica is used to repair the corrupted replica in order to stay compliant with the Dual Helix protection level.
NetApp, NetApp HCI [HCI]/1.4, x86
Data Corruption Detection, Reads/Writes, Data Availability