Package: debian-installer Severity: normal Tags: d-i The current IBM-PC style partitioner uses the no-good 255 heads, 63 sectors/track default format from 20 years ago, which misaligns partitions on just about every device (logical or hardware) that has a reason to care about something other than 512 bytes.
This results in severe performance degradation on the new HDs (4096-byte sectors exposed as 512 byte sectors), extra wear on SSDs (64, 128, 256 and 512KiB erase blocks), and RAID volumes (both hardware and software, 64, 128, 256 and 512KiB stripe sizes). Please consider forcing the partition tools to do something sensible. The most effective way is to just align everything to 1MiB, ignoring sectors/heads/cylinders entirely. One can also use a less cubersome number of heads and sectors than the default 255/63, to get better alignment. If a BIOS will break with the unaligned LBA-only partitions, it will also break with this and also have LBA32/LBA48 issues anyway, so this is not a "better compatibility choice" as far as the BIOS goes. The only advantage is that fdisk won't give you any crap about the alignment. Using 224 heads and 56 sectors per track will work for the 64KiB and 128KiB stripe sizes/erase block sizes, as well as 4KiB sectors. Using 224 heads and 48 sectors per track will work with all of the above, and also 256KiB stripes/erase blocks. Using 224 heads and 32 sectors per track will work with all of the above, and also 512KiB stripes/erase blocks. Windows deals with all of the above options just fine, AFAIK. Linux-only boxes should be using GPT anyway, but unless we are going to suggest that to the user, we should try to do better on our IBM-PC partitions. Note that forcing LVM to align its metadata area is also necessary last time I checked. Its default alignment (192KiB) is good only for 64KiB, one needs to force it to 256KiB (for 64 to 256KiB stripes/erase blocks) or 512KiB (for 64 to 512KiB stripes/erase blocks) to get proper performance. -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (500, 'testing') Architecture: amd64 (x86_64) Kernel: Linux 2.6.32.21 (SMP w/8 CPU cores) Locale: LANG=pt_BR.UTF-8, LC_CTYPE=pt_BR.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash -- To UNSUBSCRIBE, email to debian-boot-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100906212202.4877.58457.report...@khazad-dum2.khazad-dum.debian.net
