On Mon, Apr 24, 2017 at 8:19 PM, Fam Zheng <f...@redhat.com> wrote: > On Mon, 04/24 20:09, Fam Zheng wrote: >> It's a separate problem. > > To be specific: > > 1) there is an option "overlap-check" that one can use to > disable the costly metadata check; yes, i will disable metadata check, and test the performance again.
> > 2) qcow2 with cluster_size = 512 is probably too uncommon to be optimized for. if culster_size is very small, should disable metadata check default? > > Both are irrelevant to why and how this patch can be improved, IMO. > > Fam