Unfortunately, RAID does not always assure that data are available for the operating system and its users.
A pointer to a file could be wrong, for example, or pointers within the file structure could be wrong. Incomplete writes, if not properly recovered, could result in corrupt data.
Some other process could accidentally write over a file system’s structures, too.
RAID protects against physical media errors, but not other hardware and software errors.
As large as is the landscape of software and hardware bugs, that is how numerous are the potential perils for data on a system.
The Solaris ZFS file system takes an innovative approach to solving these problems through the use of checksums—a technique used to verify the