Subject: Re: Large Disks / Clean Install
To: None <>
From: Manuel Bouyer <>
List: current-users
Date: 02/08/1999 10:31:51
On Feb 6, wrote
> Yes, but this solution has its drawbacks as well, as it will
> seriously confuse the user who tries to use sysinst in it's
> near-current incarnation to install his system on such a disk,
> since sysinst at this point will insist that the disk is only
> approximately 8GB large (indeed, any disk above the 8G mark will
> be treated this way).
> What I think happens is this:
> If the new large disk to be labeled has no preexisting BSD disklabel
> (as is common), sysinst will get a "fictitious" disk label from the
> OS when it fetches the disk label information (via ioctl, I think).
> The geometry of this label will also be cropped to 16383 cylinders,
> and this will in most cases restrict the available space to a little
> under 8GB.

Is the number total of sectors also cropped ? If not it should be easy to
fix this in sysinst.

> I've found out that it is in most cases asking for
> trouble to try to bump up the number of heads to get at the
> additional space, especially if the number of heads in the disklabel
> doesn't match what the BIOS thinks about the same variable.  (Bad
> things will most likely happen in the bootstrap code.)

You should just increase the number of cylinders. Leave the other geometry
parameter as they are.

This should work if you use the upper part of the disk for NetBSD
(Then the NetBSD partition can end at 8Gb, but partitions in the disklabel
can go further), and the root partition is below to 8Gb limit.
I don't know how to handle boot partitions past the 8Gb limit, or non-netbsd
partitions past the 8Gb limit (is fdisk able to handle this now) ?

I installed NetBSD on a 9Gb scsi disk without trouble.
I used the whole disk for NetBSD, so sysinst created a 8Gb partition
on it, but in the disklabel I of course use the whole disk.

Manuel Bouyer, LIP6, Universite Paris VI.