From owner-freebsd-hackers  Sun Dec 24 00:26:52 1995
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.3/8.7.3) id AAA12902
          for hackers-outgoing; Sun, 24 Dec 1995 00:26:52 -0800 (PST)
Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19])
          by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id AAA12886
          for <hackers@freebsd.org>; Sun, 24 Dec 1995 00:26:40 -0800 (PST)
Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.9/8.6.9) id TAA22568; Sun, 24 Dec 1995 19:25:14 +1100
Date: Sun, 24 Dec 1995 19:25:14 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199512240825.TAA22568@godzilla.zeta.org.au>
To: bde@zeta.org.au, grog@lemis.de
Subject: Re: disk to disk copy
Cc: hackers@freebsd.org
Sender: owner-hackers@freebsd.org
Precedence: bulk

>> Actually, overwriting valid MBR's, SecondaryBR's (inside extended
>> partitions and disk labels should fail.  It succeeds in some cases
>> because of bugs:

>That's a matter of definition.  If you're talking to a character
>device, anything should be allowed.  I have a number of disk drives

No, character disk devices are the same as block disk devices except
the latter are buffered.

>which I use for various systems at various times.  To change systems,
>I copy the whole disk to tape and then a tape copy to disk.  Under
>FreeBSD, this always fails if there is no valid BSD label on the
>disk.  BSD/OS doesn't have this problem, so I do it with BSD/OS.

This was fixed in FreeBSD-2.0.5 for drives that report their size.

Bruce