On Wed, Nov 27, 2013 at 11:07:08AM +0100, Peter Lieven wrote: > Suggested-by: Paolo Bonzini <pbonz...@redhat.com> > Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> > Signed-off-by: Peter Lieven <p...@kamp.de> > --- > qemu-img.c | 4 ++-- > qemu-img.texi | 2 +- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/qemu-img.c b/qemu-img.c > index 9bb1f6f..8b5f3da 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -100,7 +100,7 @@ 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 (defaults to > 4k) that must\n" > + " '-S' indicates the consecutive number of bytes (defaults to > 64k) 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" > @@ -1141,7 +1141,7 @@ static int img_convert(int argc, char **argv) > QEMUOptionParameter *out_baseimg_param; > char *options = NULL; > const char *snapshot_name = NULL; > - int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */ > + int min_sparse = 128; /* Need at least 64k of zeros for sparse detection > */ > bool quiet = false; > Error *local_err = NULL;
I guess a sane size would be cluster size. For a raw file 4 KB is reasonable since that's the file system block size. Is it necessary to increase to 64 KB here?
