Why fdisk wants the first partition to start at 1 MiB?

[Francesco Turco <fturco@fastmail.fm>]

Hello.

I'm trying to use fdisk (from util-linux 2.19.1) for creating a
partition on a drive. I noticed that the start sector of the first
partition must be at least 2048, that is 1 MiB from the beginning of the
drive. This can be changed by entering the "expert mode" and using the
"move beginning of data in a partition" option. But I'm still wondering
why fdisk reserves so much space by default.

As far as I know the only sector that should not be used for partitions
is the first one, that is, sector 0. It is reserved for the MBR. So the
first partition can start at sector 1. I read that the 1 MiB thing is
Windows related: http://en.wikipedia.org/wiki/Logical_Disk_Manager. Or
it's something that Linux users should also care about? I can't find a
convincing explanation anywhere.

This 1 MiB thing seems to affect parted, too, as it wants partition
boundaries to be multiples of 1 MiB. I don't know if it's related to the
problem I have with fdisk, though.

Any help is much appreciated.