bsdlabel has no effect

[Anselm Strauss]

On Jun 28, 2008, at 13:25 , Anselm Strauss wrote:

> Hi,
>
> originally I had the following labels on my ad0 disk (no partitions,  
> directly labeled /dev/ad0):
>
> # /dev/ad0:
> 8 partitions:
> #        size   offset    fstype   [fsize bsize bps/cpg]
>  a: 1048576         0    4.2BSD     1024  8192 46248
>  c: 1048576         0    unused        0     0         # "raw" part,  
> don't edit
>
> Since this was written from a file image the my compact flash card,  
> and the card has now 8GB instead of 512MB, I wanted to grow the  
> labels after having booted the system, and that worked. So now it is:
>
> # /dev/ad0:
> 8 partitions:
> #        size   offset    fstype   [fsize bsize bps/cpg]
>  a: 15662304        0    4.2BSD     1024  8192 46248
>  c: 15662304        0    unused        0     0         # "raw" part,  
> don't edit
>
> But unfortunately, I also grew label 'a', although I did not grow  
> the filesystem. What I actually wanted was to stay 'a' the size it  
> is and add new labels. So I tried to shrink 'a' again, to finally  
> have something like:
>
> # /dev/ad0:
> 8 partitions:
> #        size   offset    fstype   [fsize bsize bps/cpg]
>  a:  1048576        0    4.2BSD     1024  8192 46248
>  c: 15662304        0    unused        0     0         # "raw" part,  
> don't edit
>
> before adding new labels. But somehow bsdlabel has no effect when  
> shrinking 'a'. No error or verbose message, the labels are just the  
> same before running it, whether I use the edit mode or restore mode.
>
> Am I not supposed to shrink a label like that?
>
> Cheers,
> Anselm
>

Okay, this was of course since I tried to resize a partition that is  
mounted. I guess this will never work, even when the filesystem  
actually already has the size the partition should be shrunk to. I  
think there is no other way of resizing the root partition/filesystem  
without booting a different system than the one on this partition.

Anselm