From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: impact of 4k sector size on the IO & FS stack Date: Mon, 12 Mar 2007 15:16:07 -0400 Message-ID: <45F5A6F7.9080108@torque.net> References: Reply-To: dougg@torque.net Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org To: Bryan Henderson Cc: Jeff Garzik , Jan Engelhardt , linux-fsdevel@vger.kernel.org, Linux-ide , linux-scsi , Ric Wheeler List-Id: linux-ide@vger.kernel.org Bryan Henderson wrote: >> DOS partitions start partitions on odd-numbered sectors > > I don't get this. If you mean partitions defined by the classic DOS > partition table format, then AFAICS, such a partition can start in any > sector. Bryan, Typically the first partition on a DOS partitioned disk starts at the next available sector after the mbr which, for some bizarre reason, is 63 sectors long. Hence: # fdisk -lu /dev/hda Disk /dev/hda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors Units = sectors of 1 * 512 = 512 bytes Device Boot Start End Blocks Id System /dev/hda1 * 63 18314099 9157018+ c W95 FAT32 (LBA) /dev/hda2 18314100 19551104 618502+ 82 Linux swap / Solaris /dev/hda4 19551105 156296384 68372640 83 Linux > >> so presuming you have odd-aligned disks, life is good. > > What is an odd-aligned disk? s/disk/partition/ ? Perhaps hda1 and hda4 above are examples. Doug Gilbert