gmirror problem on 5.3-R i386

Doug Poland doug at
Thu Jan 13 22:38:05 PST 2005

On Thu, Jan 13, 2005 at 09:51:03AM +0100, Christian Hiris wrote:
> On Thursday 13 January 2005 03:54, Doug Poland wrote:
> >
> > # dd if=/dev/zero of=/dev/ad4 bs=512 count=79
> You probably destroyed your slice table here. The dd command only
> makes sense if you insert whole disks (ie. /dev/ad4 and /dev/ad6) as
> providers. Otherwise you need to create (or already have) a valid
> slice table on the disk, which enables gmirror to locate and insert
> your slice. 
I wonder why it's documented to do that?  Guess that proves I'm too
green to understand the consequences of my actions.

> (!) Before you start to correct your gmirror setup, please read all of
> my comments, because to me it looks like you run a mirror of ad6 and
> not ad6s1.    
I'm quite sure I entered ad6s1 as opposed to ad6 in my commands.
In retrospect, however, I think I horked up my bsdlabel for
/dev/mirror/gsm0.  I didn't set the offset for the a partition to 16.
Perhaps that accounts for the difference?

While I was waiting for a reply I messed around with the configuration
and throughly broke it.  It's no big deal as this is a brand new server
with nothing on it but a minimal install.  I want to get this gmirror
working and understand it before I put the box into production.

I decided to start over (re-install 5.3) and go through the instructions
more carefully.  I'll email the list if I have more/other problems,
thanks for your help.


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