On 20/03/2017 14:35, Peter Lieven wrote: > Am 20.03.2017 um 14:23 schrieb Paolo Bonzini: >> On 20/03/2017 14:13, Peter Lieven wrote: >>> Am 20.03.2017 um 13:47 schrieb Peter Lieven: >>>> commit 5daa74a6ebce7543aaad178c4061dc087bb4c705 >>>> Author: Paolo Bonzini <pbonz...@redhat.com> >>>> Date: Wed Sep 4 19:00:38 2013 +0200 >>>> >>>> block: look for zero blocks in bs->file >>>> >>>> Reviewed-by: Eric Blake <ebl...@redhat.com> >>>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> >>>> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> >>>> >>>> >>>> It was introduced while introducing bdv_get_block_status. I don't know >>>> what the real >>>> >>>> issue was that was addressed with this patch? >>> Is it possible that this optimization was added especially for RAW? I was >>> believing that >>> raw would forward the get_block_status call to bs->file, but it looks it >>> doesn't. >>> If this one here was for RAW would it be an option to move this callout to >>> the raw-format driver >>> and remove it from the generic code? >> It was meant for both raw and qcow2. > > Okay, but as Fam mentioned qcow2 Metadata should know that a cluster is zero. > Do you remember > what the issue was?
I said that already---preallocated metadata. Also, at the time pre-qcow2v3 was more important. Are you using libiscsi, block devices or files? Paolo
