[Buildroot] [PATCH] manual: add section about dealing efficiently with big image files

[Peter Korsgaard <jacmet@uclibc.org>]

>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

Hi,

 > I'll remove it before re-submitting. After all, we hint to the man pages
 > of other tools, so it's thoroughly documented. And if anyone if foolish
 > enough to try that, then we can say 'we never wrote that!' :-)

Indeed, thanks ;)

 >> I think that you should be using bigger block sizes, tools that
 >> understand the filesystem layout or resize afterwards (E.G. resize2fs)
 >> instead.

 > Not sure I follow you on that one. What if the user enters a large
 > number of blocks for his ext2 filesystem? Those will be empty
 > (zero-filled), but the image file will not be made sparse. So there is
 > no 'fs resize' or such in the process.

What I meant was simply that if you want to end up with a filesystem
with lots of free space and don't want to waste time writing zeroes to
the unused areas, it is safer to:

 - create the filesystem spanning the entire partition yourself on the
   fly (mkfs + tar xf output/images/rootfs.tar)

 - or resize fs to the full partition size after writing the image
   (dd if=output/images/rootfs.ext2 + resize2fs)

-- 
Bye, Peter Korsgaard