http://www.cidrdb.org/cidr201... «[In some HDDs,] data is written partially overwriting preceding tracks. The data in the middle of the band cannot be overwritten without trashing the rest of the band. To overcome this, the hardware disk controllers implement log-structured file systems within the disk controller.»
«The operating system is unaware of the use of shingles. What’s written to the disk (i.e. the band of data written with shingles) remains unchanging until it is discarded. The user of the disk (e.g. the operating system) perceives the ability to update in place.» #hardware_is_crazy - 9000