Hello, On 03/10/2010 06:14 PM, Denys Vlasenko wrote: > 63s/255h is more or less "standard" now. > > Alignment issues can be solved by picking a good multiple of > _heads_ or _cylinders_: I've got a couple of comments stating that picking a good geometry parameters can resolve the whole issue but I simply fail to see how it could. We can pick any parameter we wish, but there is no reliable way to communicate the custom geometry parameters to others. Geometry is determined by two parameters sec/trk and heads/cyl. You can punch in those numbers if the BIOS has a menu for it (many don't these days). Or hope that BIOS can somehow figure it out from the partition table which some BIOSs actually try to do. The problem is that to determine the two parameters you need to equations matching CHSs and LBAs and that's available iff the first partition ends before CHS addressing limit according to the custom geometry, which usually is not the case. So, custom geometry is only useful to trick partitioners which align using cylinders into using better alignments but doesn't help anything for compatibility as no one can determine the used geometry reliably after the partitioning is complete. With compatibility benefit gone, there simply is no reason to stick to the cylinder abstraction at all. Am I missing something? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
