Il 13/09/2013 21:48, Peter Lieven ha scritto: > Am 13.09.2013 20:25, schrieb Eric Blake: >> On 09/13/2013 04:36 AM, Paolo Bonzini wrote: >>> Il 13/09/2013 12:25, Peter Lieven ha scritto: >>>> if the target has_zero_init = 0, but supports efficiently >>>> writing zeroes by unmapping we call bdrv_zeroize to >>>> avoid fully allocating the target. this currently >>>> is designed especially for iscsi. >>>> >>>> Signed-off-by: Peter Lieven <p...@kamp.de> >>>> --- >>>> qemu-img.c | 22 ++++++++++++++++------ >>>> 1 file changed, 16 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/qemu-img.c b/qemu-img.c >>>> index 3e5e388..6eaddc6 100644 >>>> --- a/qemu-img.c >>>> +++ b/qemu-img.c >>>> @@ -1354,7 +1354,8 @@ static int img_convert(int argc, char **argv) >>>> } >>>> } >>>> >>>> - flags = BDRV_O_RDWR; >>>> + flags = BDRV_O_RDWR | BDRV_O_UNMAP; >>> I think this should be a new command-line flag. >> I agree - while 'sparse by default' may be reasonable, it is also >> feasible to want a mode that guarantees expansion rather than unmapped >> or sparse. >> > Ok, so do you find the proposed -S 0 bei Paolo a good choice? > If this is supplied I would go as far as completly setting > has_zero_init = 0 also for targets which default to 1. This > would guaranteed exspansion and full allocation for all drivers.
Sounds good. Paolo