On 1046023914 seconds since the Beginning of the UNIX epoch
Anne Bennett wrote:
>

>I do believe that there may be a bug in the DIOCWDINFO ioctl, though.
>I looked a bit at disklabel.c, and, as per the comment in it, the
>disklabel is read differently based on the flags.  If "-r" or "-I" is
>given, the disk label is read from the raw device using an offset
>calculated in disklabel.c; that worked properly all along.  If neither
>of those flags in specified, then the DIOCWDINFO ioctl is used to
>fetch the label, and that failed until I zeroed out part of my disk
>and reinstalled the MBR and disklabel from scratch.  Therefore, it
>seems as though DIOCWDINFO is confused by the presence of additional
>label or MBR-like material on the disk.

Well, the logic in disklabel(8) is a bit more complicated that the
logic in the kernel.  disklabel -r will scan the front or the disk
[using the raw device] for the disklabel, whereas the kernel will
look for the disklabel in a fixed position.  You notice this
especially if you move a disk from, e.g. an alpha to an i386.
disklabel -r will find the alpha's disklabel, but the kernel will
not because on the i386 the disklabel is offset from the start of
the partition whereas on the alpha it isn't.

--
    Roland Dowdeswell                      http://www.Imrryr.ORG/~elric/