[parted-devel] [PATCH] use 1MB partition alignment with GPT and disks with !512b sector sizes

[Matt Domsch]

This creates a new 1MB start alignment constraint, and has GPT use it
when disks have a logical block size != 512 bytes.  This might need to
be extended to do so if the disk has a physical sector size != 512
bytes as well, for the case of 512b logical, 4k physical sectors,
where we really want the partitions on 4k boundaries at least.

Note, Vista uses a 1MB partition alignment always now, where XP and
earlier used the standard cylinder boundary.  We might want to default
parted to using 1MB alignments always, but to not overwrite exising
partition layouts.

Note also, I haven't seen parted code to handle "odd alignment".
http://lists.alioth.debian.org/pipermail/parted-devel/2007-December/002055.html
http://www.idema.org/_smartsite/modules/local/data_file/show_file.php?cmd=download&data_file_id=1719
describes T13 Identify Device command, word 209, which shows how to
get this alignment. It seems future SATA disks will use "odd
alignment" as that's what XP used, but for SCSI that isn't determined
yet.

Fun fun.