Re: debian-installer: how to exactly specify partition sizes?

[Andy Smith <andy@strugglers.net>]

Hi Pascal,

On Sun, Jul 13, 2025 at 09:30:59AM +0200, Pascal Hambourg wrote:
> On 12/07/2025 at 14:03, Andy Smith wrote:
> > i.e. given existing partman-installed system:
> > 
> > $ head -6 /proc/partitions
> > major minor  #blocks  name
> > 
> >     8       16 1875374424 sdb
> >     8       17     487424 sdb1
> >     8       18     976896 sdb2
> >     8       19    1952768 sdb3
> > 
> > I could ask for exact sizes:
> > 
> > $ echo "487424*512 + 1024" | bc
> > 249562112
> > $ echo "976896*512" | bc
> > 500170752
> > $ echo "1952768*512" | bc
> > 999817216
> 
> Sizes in /proc/partitions are in KiB, not 512-byte sectors.

Oh, yeah. That was a copy/paste from some earlier failed experiment. :)

Is the above theory sound though for a GPT label? i.e. first one 487424
* 1024 + 1024, second and further ones just multiply by 1024. Last one
expect a bit at the end reserved for possible MD metadata.

(I don't actually care about the last one as the last one is usually
always "the rest of the available device however partman wants," for
me.)

Thanks,
Andy