Verification steps: 1.qemu-img create -f qcow2 data1.img 10M qemu-img create -f qcow2 -b data1.img data1.qcow2
2.write 1M data to data1.img 3.create vm use data1.qcow2 as the data disk /usr/libexec/qemu-kvm -M pc,accel=kvm -smp 4 -cpu host -m 4g -drive file=./centos_7.5_64_20200603.qcow2,if=none,id=drive-virtio0,cache=none, aio=native -device virtio-blk-pci,drive=drive-virtio0,id=virtio0 -drive file=./data1.qcow2,if=none,id=drive-virtio1,cache=none,l2-cache-size= 1048576,aio=native -device virtio-blk-pci,drive=drive-virtio1,id=virtio1 -vnc :101 -qmp stdio 4.{"execute": "block-stream", "arguments":{"device":"drive-virtio1"}} 5.kill -9 $(pidof qemu-kvm) 6.md5sum data1.img data1.qcow2,check if it is the same Evanzhang (1): block/stream:add flush l2_table_cache,ensure data integrity block/stream.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.9.5