On Tue, 14 Apr 2009, Jeff Garzik wrote: > Avi Kivity wrote: > > Jeff Garzik wrote: > > > Speaking of RMW... in one sense, we have to deal with RMW anyway. > > > Upcoming ATA hard drives will be configured with a normal 512b sector API > > > interface, but underlying physical sector size is 1k or 4k. > > > > > > The disk performs the RMW for us, but we must be aware of physical sector > > > size in order to determine proper alignment of on-disk data, to minimize > > > RMW cycles. > > > > > > > Virtualization has the same issue. OS installers will typically setup the > > first partition at sector 63, and that means every page-sized block access > > will be misaligned. Particularly bad when the guest's disk is backed on a > > regular file. > > > > Windows 2008 aligns partitions on a 1MB boundary, IIRC. > > Makes a lot of sense... Since Vista at least the first partition is 2048 sector aligned. Szaka -- NTFS-3G: http://ntfs-3g.org -- 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
