gpart oddity

Vadim Goncharov vadim_nuclight at
Mon Nov 10 03:41:27 PST 2008

Hi Marcel Moolenaar! 

On Wed, 05 Nov 2008 09:28:19 -0800; Marcel Moolenaar wrote about 'Re: gpart oddity':

>> The question is, how much strict it is? Currently I have an 6.2-S  
>> system with
>> gmirror(8)'ed slices, not disks, as it was converted from existing  
>> system
>> with different sizes of disks. I have had edit their labels that  
>> partition
>> 'c' doesn't cover entire unit (and last partition was reformatted to  
>> be not
>> truncated, too). This is needed to be sure that last sector gets not
>> overwritten by gmirror(8) metadata, but bsdlabel(8) always complains  
>> about it
>> that it doesn't cover bla-bla-bla. Moreover, labeled partitions and  
>> slices
>> exist on their own, despite of gmirror(8). And yet more, if I try to  
>> do a
>> bsdlabel(8) on a gm0, it will complain about 63 sectors boot offset,  
>> while
>> on ad0s1 it will not, so I need to hack a lot if I need to resize  
>> partitions.
>> What is the cause of the trouble?
>  From what you tell, I think the problem is caused by
> forcing the proverbial square peg into the proverbial
> round hole.
> We made it too easy for people to create invalid labels
> because we simply didn't do any real sanity checking
> and/or didn't provide any real tools to help the user
> achieve what they want.
> The fact that gmirror puts the metadata in the last
> sector and only adjusts the media size of the provider
> when in use, means that we have introduced ambiguity
> in how the GEOMs are stacked and while the gmirror
> approach is a feature on the one hand, we have done so
> without regard for the validity of disklabels. We
> handwaved the problems as unimportant or aesthetic.

But the question is, what I will have to do with my setup? Will it still work
in future versions?

WBR, Vadim Goncharov. ICQ#166852181       mailto:vadim_nuclight at
[Moderator of RU.ANTI-ECOLOGY][FreeBSD][][LJ:/nuclight]

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