Comment by userbinator

One of the more surprising facts revealed in this article is that modern HDDs don't go through the traditional CHS order with increasing LBAs, and the number of sectors per track can vary even between two sides of the same platter at the same radial distance. I suspect a lot of this information is kept secret by HDD manufacturers, and known only to them and those working in data recovery (if a drive has one dead head, or media damage on one surface, traditional CHS order vs. the others would show very different results in which portions remain readable.)