Dealing with filesystem and database corruption

The cost of fixing a trusted system that has become untrusted is much greater than the cost of maintaining a trusted system. Once trusted, you can use a few procedures to monitor the integrity of the system. Filesystem corruption is an infrequent occurrence, but can result in the removal of files that are critical to the continued operation of your system. This notion of system integrity is different from dealing with tampering, which is the deliberate action of a malicious user to alter or access data. This section explains the important security database files and how to recover them in the event of a system crash.