Re: Large disk access

[Rakhesh Sasidharan <rakhesh@cse.iitd.ac.in>]

> I do not know enough about how using the entire disk on OpenBSD works, but
> there was a thread about this on FreeBSD mailing lists a while back which
> concluded that although by using this mode (named dd in FreeBSD) you can
> save a bit of disk space and also may be able to not care about BIOS
> geometries, some machines that do not contend themselves with the fake
> partition table created in such a case but actually require a vaild fidsk
> table in there will not boot in this dedicated mode. Also as I have heard
> such disks are not "portable" ie you cannot simply take them out and pop
> 'em into another case after partitioning them this way, which IMHO also
> sucks. For these and a couple related resons this mode is now not even
> offered in FreeBSD upon installation so that only those who understand what
> they are doing fiddle with it. All others are encouraged to use fdisk.

Quite true.  I have just worked on FreeBSD 3.2 and 3.4 before I decided to
switch to OpenBSD fulltime; but I did read that time that dd (dangerously
dedicated, as it is called; coz you dedicate the whole disk to FreeBSD :)
has problems like you said.  And even then the installation program
advised me not to use it.

> As I gather this is an "ideological limitation" in OpenBSD (which is quite
> alone with this among all the PC OSs...) but I wonder if it will stay this
> way... I think the choice and opportunity should be there, and not only in
> the form of a Windows boot floppy... after all, BSDs are all about choice,
> right?

Err ... Linux, performs quite well in this regard.  In fact, if the Linux
fdisk would not have managed to handle my disks that well (by Linux, I
mean the newer ones like RedHat 6.1 and upwards), I would have thought
that this was some problems with BIOS and things in general.

But tell me, how does one use a Win boot floppy to allocate space for
OpenBSD ?  I think you can carve a space for OpenBSD, but how do you then
change its type to "A6" ?  I ask this coz I made Linux allocate a space
for OpenBSD to use, and then tried to change its type from OpenBSD's
fdisk, but it refused to ... reason: the sectors were exceeding fdisk's
view of it.  I then had to make Linux change the type to "A6", and even
though OpenBSD now views it as "A6", my GRUB refuses to accept it.  But
that's another (bother) story ...

Regards,
Rakhesh