On Mon, Mar 8, 2010 at 11:22 AM, jim owens <owens6336@xxxxxxxxx> wrote: > David Newall wrote: >> Christian Borntraeger wrote: >>> Some bigger things are missing in the e4defrag tool: >>> ... >>> - overall layout considerations (e.g. putting files close to its >>> directory or >>> use the atime to move often used files to the beginning of a disk etc.) >> >> Shouldn't oft-used files be placed closer to the middle? If you place >> them at the beginning of the file, it's only possible for the head-stack >> to be close to the file from the inner direction. Place them in the >> middle and it's possible for the head-stack to be close from the outer >> direction, too, which sounds like a doubling of probability. It seems >> that it's the least frequently used files that should be placed at one >> end of the disk or the other. > > No. Your logic would be correct if rotating disks had > similar speed at all locations. Current disks are much > faster at the 0 end than at the middle or highest address. > > It is not unusual to see 2x difference in transfer speed > so you always want the important stuff as low as possible. > > jim Jim, I should know this, but is sector 0 on the outside edge, or the inner edge? I assume outer so that the linear speed of the platter under the head is faster and thus more data per second is passing under the head. Greg -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
