Ensure file system integrity in embedded systems

The ability to store and manage large amounts of data has become a critical requirement for a variety of embedded devices. Car infotainment units, industrial automation systems, medical devices, media servers and portable music players are all using hard drives and other mass storage technologies in ways that no one thought possible only a few years ago.

In many cases, these systems must survive years of constant use, even when handling massive numbers of file reads and writes. Users never expect to lose data or to endure long data-recovery times.

The problem is that many embedded systems operate in hostile environments such as the automobile, where power can fluctuate or fail unexpectedly. Such events can easily corrupt data stored on hard drives and other storage media, resulting in loss of critical information. Consequently, the file system software that manages the data on the storage device must do more than provide fast read and write performance; it must also prevent data corruption caused by power failures. Moreover, it must eliminate the time-consuming file-system integrity checks typically required after a power failure since in most cases, embedded systems must be fully operational immediately after rebooting.

Unfortunately, traditional block-based file systems for hard drives or solid state drives (SSDs) were never designed to ensure file integrity in the event of power failures and other sudden shutdowns. Some file systems (e.g. ZFS) for high-availability corporate servers provide such protection, but they consume too many system resources to be used in embedded devices. The QNX power-safe file system address these problems by implementing advanced server-level techniques in an efficient, embeddable solution, thereby providing the data integrity essential to today's storage-hungry embedded applications.

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