update to 8.0-RELEASE --> partition gone

[Andriy Gapon]

on 16/12/2009 11:28 Marian Hettwer said the following:
> Hej Marcel,
> 
> 
> On Tue, 15 Dec 2009 16:46:27 -0800, Marcel Moolenaar <xcllnt at mac.com>
> wrote:
>> Yes, if you have ad2a and not ad2s1a, then you have a
>> proper dangerously dedicated disk and FreeBSD 8.x will
>> work correctly with your disk.
>>
>> If you installed "dangerously dedicated" and ended up
>> with ad0s1a (note the "s1"), then you have an invalid
>> partitioning and FreeBSD 8.x will not give you what
>> you've been getting on FreeBSD 7.x. Most of the time
>> you only need to wipe out the second sector on the
>> disk to clean it up and have FreeBSD 8.x also give
>> you ad0s1a.
>>
> okay... but how do I wipe out the second sector?
> dd if=/dev/zero of=/dev/ad8 count=1
> would wipe out the first 512 bytes.

You need to add seek=1 (or oseek=1, which is the same but a little bit more
obvious) to that command.

> I'm always confused with sectors vs.
> bytes.

You are not confused this time, HDD sector is 512 bytes.  This is the default dd
block size too.

-- 
Andriy Gapon