Home > Data Protection > PowerProtect DD Series Appliances > PowerProtect Appliance Data Invulnerability Architecture > Fault avoidance and containment
The next step in protecting the data is to ensure that the data, which was verified to be correct, stay correct. Ironically, the biggest risk to file system integrity is file system software errors that occur when new data is written. Only new writes can accidentally write on existing data, and only new updates to file system metadata can mangle existing structures.
Because the Data Domain file system was built to protect data as its primary goal, its design protects against even its own software errors that could put existing data at risk. It accomplishes this through a combination of design simplicity, which reduces the chance of software issues in the first place, and several fault containment features, which make it difficult for potential software errors to corrupt existing data. PowerProtect Appliance systems are equipped with a specialized log-structured file system that has four important benefits: