Re: large disks

["Thomas Mueller" <mueller23%insightbb.com@localhost>]

from neoluddite%hushmail.com@localhost:

> I recently upgraded to a 3TB hard disk and the 6.0_RC2 installer does
> not recognize it even though the bios does.  Is there anything special
> that must be done to use large hard disks?

Large disks would need to be partitioned by GPT rather than fdisk and mbr,
since fdisk and mbr can only go up to 2 TB.

You would not use a traditional BSD disklabel with GPT.

I think you can boot NetBSD or FreeBSD from a GPT partition using grub2
with something like

set root=(hd1,gpt3) # or wherever it actually is
knetbsd /netbsd # assuming kernel is /netbsd
boot

or for FreeBSD,

set root=(hd1,gpt3) # or wherever it is
kfreebsd /boot/loader
boot

In the case of FreeBSD, this is explained in /usr/ports/sysutils/grub2 .

An easy way to get grub2 is to download and burn, or write to USB stick, 
the System Rescue CD (sysresccd.org).  You will also see how Linux views the
large hard disk.

NetBSD deals with GPT disks through dk-wedges (/dev/dk0, /dev/dk1, ..), but
this sequence spans all GPT-partitioned disks; FreeBSD and Linux are much more
elegant.  But NetBSD's installer, sysinst, can't deal with GPT disks at all,
and also can't deal with already-mounted partitions.  I know from painful
experience last year before FreeBSD 9.0-BETA1 was released, which took me
away from NetBSD for a long time.

A useful program/package for dealing with GPT is Rod Smith's gdisk
http://rodsbooks.com/gdisk/

Linux and FreeBSD are more advanced than NetBSD dealing with large disks 
using GPT, also in supporting USB 3.0 and devfs.

Tom