glabel, gmirror, and gpart

[Warren Block]

On Fri, 26 Aug 2011, Adam Vande More wrote:

> On Fri, Aug 26, 2011 at 8:09 PM, Warren Block <wblock at wonkity.com> wrote:
>       Question 2 is maybe simpler.  On boot, it shows this:
>        gptboot: invalid backup GPT header
>
>       I can speculate on what causes that (whether the various g-things use the absolute last block of the device, or the last block of their area and provide their total minus
>       one block; or it could be that gptboot is seeing the disk rather than the gmirror device).  Can it be fixed?
> 
> 
> This is a long standing issue that still isn't fixed to the best of my knowledge.  The problem is with gmirror and GPT. 
> 
> http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=auto&tl=en&u=http%3A%2F%2Fbu7cher.blogspot.com%2F2011%2F03%2Ffreebsd-gmirror-gpt-ufs.html&act=url
> 
> is the best I can do.

Thanks!

So it's cosmetic, but not really the kind of message that instills 
confidence.  gptboot needs to be able to tell if it's reading from a 
gmirror.  Or gmirror should provide one block less than it does, so it 
doesn't overwrite the GPT backup.