On 2015-01-15 18:08:39, Paolo Bonzini wrote: > > On 15/01/2015 10:56, Zhang Haoyu wrote: > > I see, when waiting the completion of drive_mirror IO, the coroutine will be > > switched back to main-thread to poll and process other events, like qmp > > request, > > then after the IO completed, coroutine will be switched back in main-loop > > process, right? > > > > Another question: > > while starting to migrate storage, will the unused sector be allocated and > > transferred? > > regarding the thin-provisioning qcow2 disk, will extra large IO requests be > > performed, and more data be transferred for the unallocated clusters? > > No. > My test results show that when using thin-provisioning qcow2 image(created by qemu-img create -f qcow2 preallocation=metadata), even the unallocated sectors will be transferred to destination, so much data is transferred, so the qcow2 image in destination is full allocated.
Thanks, Zhang Haoyu > Paolo
