Jochen Schulz put forth on 12/13/2010 3:51 PM: > Mike Viau: >>> On Mon, 13 Dec 2010 21:46:59 +0100 <m...@well-adjusted.de> wrote: >>> >>> Partition 1 does not start on physical sector boundary. >> >> I don't understand the implied meaning of this error? Did you take any >> precautions as to the alignment of your partition? What about if you >> were planning on having multiple partitions?
>From the linux-ide mailing list April 2010: http://www.spinics.net/lists/linux-ide/msg37306.html Unfortunately, sfdisk and cfdisk have no clue about alignment and disks topology. Now only the fdisk and parted commands are ready for new disks. So the proper title of this thread should be: "Does the Squeeze installer use fdisk or parted?" As of April 2010, only fdisk and parted will create sector boundary aligned partitions on drives that internally translate from 4K to 512B sectors. Linux typically reads 4K blocks. With a translated drive, two or more 512 byte sectors of a given block may lie on opposite sides of a hardware 4K sector boundary. Thus, Linux will have to read two consecutive hardware sectors instead of one in order to get the contents of the 4K logical block. I.e. two reads (head seeks) per every 4k block instead of one. Thus, you get half the performance vs a properly aligned cylinder. In the case of the WD20EARS this will drop your peak sequential read rate from over 100 MB/s down to 50 MB/s or less. Without proper alignment, you're literally leaving half of your drive's sequential read performance on the table. The story is even worse for 4K random writes. You'll drop your write performance by a factor of 4 or more if you don't have proper alignment: The moral of the story is, use fdisk or parted and make sure your partitions are correctly aligned on 4KB boundaries. If the Squeeze installer doesn't do so, I'd recommend booting an ISO or USB live distro and partition the drive with fdisk or parted before booting the Squeeze installer. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4d06aefa.6070...@hardwarefreak.com