Re: [PATCH 1/2] wic/utils/partitionedfs.py: assemble .wic images as sparse files

[Robert Yang <liezhi.yang@windriver.com>]

On 04/08/2016 05:14 PM, Joshua Lock wrote:
> From: Joshua Lock <joshua.lock@collabora.co.uk>
>
> The individual partitions created by wic are sparse but without
> this change the assembled image is written as one (potentially
> very) large file.
>
> Preserve sparseness in the assembled image by passing the sparse
> conversion symbol.
>
> [YOCTO #9099]
>
> Signed-off-by: Joshua Lock <joshua.lock@collabora.co.uk>
> ---
>   scripts/lib/wic/utils/partitionedfs.py | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/lib/wic/utils/partitionedfs.py b/scripts/lib/wic/utils/partitionedfs.py
> index 5a103bb..3e2b420 100644
> --- a/scripts/lib/wic/utils/partitionedfs.py
> +++ b/scripts/lib/wic/utils/partitionedfs.py
> @@ -340,7 +340,7 @@ class Image(object):
>               source = part['source_file']
>               if source:
>                   # install source_file contents into a partition
> -                cmd = "dd if=%s of=%s bs=%d seek=%d count=%d conv=notrunc" % \
> +                cmd = "dd if=%s of=%s bs=%d seek=%d count=%d conv=notrunc,sparse" % \

Hi Joshua,

I got errors with this patch since my dd doesn't support conversion sparse:
dd: invalid conversion: `sparse'
Try `dd --help' for more information.

So that it would fail.

$ dd --version
dd (coreutils) 8.13
Copyright (C) 2011 Free Software Foundation, Inc.

The host is Ubuntu 12.04, it works well except this error.

// Robert

>                         (source, image_file, self.sector_size,
>                          part['start'], part['size'])
>                   exec_cmd(cmd)
>