Hi, I'm currently planning to migrate our storage to ceph/rbd through qemu drive-mirror
and It seem that drive-mirror with rbd block driver, don't create a sparse image. (all zeros are copied to the target rbd). Also note, that it's working fine with "qemu-img convert" , the rbd volume is sparse after conversion. Could it be related to the "bdrv_co_write_zeroes" missing features in block/rbd.c ? (It's available in other block drivers (scsi,gluster,raw-aio) , and I don't have this problem with theses block drivers). Regards, Alexandre Derumier
