NanoBSD: Create image sparsely

[Warner Losh]

Looks good to me, go ahead.

Warner

On Nov 29, 2012, at 12:42 AM, Nick Hibma wrote:

> In the past I have submitted patches to create images sparsely. There is however one patch missing still which, with the addition of NANO_INIT_IMG2, has become much more useful:
> 
> --- AnyWi/freebsd/nanobsd/nanobsd.sh     2012-11-08 19:48:40.000000000 +0100
> +++ /usr/src/tools/tools/nanobsd/nanobsd.sh 2012-11-06 15:24:52.000000000 +0100
> @@ -540,7 +540,7 @@
>        if [ $NANO_IMAGES -gt 1 -a $NANO_INIT_IMG2 -gt 0 ] ; then
>              # Duplicate to second image (if present)
>               echo "Duplicating to second image..."
> -         dd if=/dev/${MD}s1 of=/dev/${MD}s2 bs=64k
> +               dd conv=sparse if=/dev/${MD}s1 of=/dev/${MD}s2 bs=64k
>              mount /dev/${MD}s2a ${MNT}
>             for f in ${MNT}/etc/fstab ${MNT}/conf/base/etc/fstab
>           do
> @@ -569,7 +569,7 @@
> 
>       if ${do_copyout_partition} ; then
>              echo "Writing out _.disk.image..."
> -              dd if=/dev/${MD}s1 of=${NANO_DISKIMGDIR}/_.disk.image bs=64k
> +          dd conv=sparse if=/dev/${MD}s1 of=${NANO_DISKIMGDIR}/_.disk.image bs=64k
>   fi
>     mdconfig -d -u $MD
> 
> It copies out the image sparsely (conv=sparse). The big advantage comes when creating many images (I have between 10 and 20 images simultaneously on my disk).
> 
> Any objections to this? (*)
> 
> Nick Hibma
> nick at van-laarhoven.org