Commit 11b6699a authored by Peter Lieven's avatar Peter Lieven Committed by Kevin Wolf

qemu-img: add support for fully allocated images

Signed-off-by: default avatarPeter Lieven <pl@kamp.de>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent c3d86884
......@@ -100,8 +100,12 @@ static void help(void)
" '-h' with or without a command shows this help and lists the supported formats\n"
" '-p' show progress of command (only certain commands)\n"
" '-q' use Quiet mode - do not print any output (except errors)\n"
" '-S' indicates the consecutive number of bytes that must contain only zeros\n"
" for qemu-img to create a sparse image during conversion\n"
" '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
" contain only zeros for qemu-img to create a sparse image during\n"
" conversion. If the number of bytes is 0, the source will not be scanned for\n"
" unallocated or zero sectors, and the destination image will always be\n"
" fully allocated\n"
" images will always be fully allocated\n"
" '--output' takes the format in which the output must be done (human or json)\n"
" '-n' skips the target volume creation (useful if the volume is created\n"
" prior to running qemu-img)\n"
......@@ -1465,7 +1469,7 @@ static int img_convert(int argc, char **argv)
/* signal EOF to align */
bdrv_write_compressed(out_bs, 0, NULL, 0);
} else {
int has_zero_init = bdrv_has_zero_init(out_bs);
int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0;
sector_num = 0; // total number of sectors converted so far
nb_sectors = total_sectors - sector_num;
......
......@@ -193,6 +193,12 @@ Image conversion is also useful to get smaller image when using a
growable format such as @code{qcow} or @code{cow}: the empty sectors
are detected and suppressed from the destination image.
@var{sparse_size} indicates the consecutive number of bytes (defaults to 4k)
that must contain only zeros for qemu-img to create a sparse image during
conversion. If @var{sparse_size} is 0, the source will not be scanned for
unallocated or zero sectors, and the destination image will always be
fully allocated.
You can use the @var{backing_file} option to force the output image to be
created as a copy on write image of the specified base image; the
@var{backing_file} should have the same content as the input's base image,
......
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