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From: John Baldwin <jhb@freebsd.org>
To: Roman Kurakin <rik@inse.ru>
Date: Mon, 7 Aug 2006 17:41:24 -0400
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Cc: freebsd-hackers@freebsd.org, Dmitry Marakasov <amdmi3@mail.ru>,
	Dag-Erling Sm?rgrav <des@des.no>
Subject: Re: absolute vs. relative offsets in disklabel
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On Monday 07 August 2006 17:05, Roman Kurakin wrote:
> John Baldwin:
> 
> >On Sunday 06 August 2006 10:59, Dmitry Marakasov wrote:
> >  
> >
> >>* Dag-Erling Sm?rgrav (des@des.no) wrote:
> >>    
> >>
> >>>>Recent `disklabel differences FreeBSD, DragonFly' thread gave me a
> >>>>thought - why do we have absolute offsets in disklabel?
> >>>>        
> >>>>
> >>>We don't, AFAIK.  Since the transition to GEOM, the offsets are
> >>>relative to the start of the containing provider.
> >>>      
> >>>
> >>It has nothing to do with GEOM, it's ondisk format of disklabel. I've
> >>confirmed, there are global offsets.
> >>    
> >>
> >Actually, the GEOM provider goes though some gymnastics to portray the 
offsets 
> >as relative to userland, but ondisk they are still stored as absolute to 
> >preserve compatiblity.
> >  
> >
> You mean that "read mbroffset" to geom could return a relative value?

No, this is specific to the BSD label class, not something GEOM does in 
general.

-- 
John Baldwin