8.3-BETA1 installation problem

[Michael Powell]

Warren Block wrote:

> On Fri, 24 Feb 2012, Omer Faruk SEN wrote:
> 
>> Already done that but still habe the same issue. I can dd and sysctl but
>> after installing without using W at disk label screen still no luck. I
>> have also done
>> sysctl kern.geom.debugflags=16 on fixit and restarted installation but
>> still getting the same error.
> 
> [Please don't top-post, it makes responding more difficult.]
> 
>>> If you need to clear the old MBR the "old way", use a LiveFS or Fixit
>>> shell and do this (as root):
>>>
>>> sysctl kern.geom.debugflags=16  and:
>>>
>>> dd if=/dev/zero of=/dev/adx oseek=1 bs=512 count=1
> 
> The sysctl is not necessary.  The dd may not erase enough of the disk.
> It will erase a bsdlabel, but not the MBR/PMBR.  As always, be warned
> that this will erase the partition table on that disk, so make sure it's
> the correct target disk and that you have full backups:
> 
>    dd if=/dev/zero of=/dev/adX bs=512 count=34
                                                                                          ^^^^^^^^
Excellent idea here. It covers GPT too, for as if a Linux distro was on the 
disk previously, or anything else using GPT. For me I only needed the one 
because my problem was only a change from FBSD 6.2 to 7.x something, 
no GPT involved - my problem was only disklabel related.
 
> Replace X with the correct drive number.