am testing QEMU COLO feature described here [QEMU Wiki](http://wiki.qemu-project.org/Features/COLO).
When the Primary Node panic,the Secondary Node qemu hang. hang at recvmsg in qio_channel_socket_readv. And I run { 'execute': 'nbd-server-stop' } and { "execute": "x-colo-lost-heartbeat" } in Secondary VM's monitor,the Secondary Node qemu still hang at recvmsg . I found that the colo in qemu is not complete yet. Do the colo have any plan for development? Has anyone ever run it successfully? Any help is appreciated! centos7.2+qemu2.7.50 (gdb) bt #0 0x00007f3e00cc86ad in recvmsg () from /lib64/libpthread.so.0 #1 0x00007f3e0332b738 in qio_channel_socket_readv (ioc=<optimized out>, iov=<optimized out>, niov=<optimized out>, fds=0x0, nfds=0x0, errp=0x0) at io/channel-socket.c:497 #2 0x00007f3e03329472 in qio_channel_read (ioc=ioc@entry=0x7f3e05110e40, buf=buf@entry=0x7f3e05910f38 "", buflen=buflen@entry=32768, errp=errp@entry=0x0) at io/channel.c:97 #3 0x00007f3e032750e0 in channel_get_buffer (opaque=<optimized out>, buf=0x7f3e05910f38 "", pos=<optimized out>, size=32768) at migration/qemu-file-channel.c:78 #4 0x00007f3e0327412c in qemu_fill_buffer (f=0x7f3e05910f00) at migration/qemu-file.c:257 #5 0x00007f3e03274a41 in qemu_peek_byte (f=f@entry=0x7f3e05910f00, offset=offset@entry=0) at migration/qemu-file.c:510 #6 0x00007f3e03274aab in qemu_get_byte (f=f@entry=0x7f3e05910f00) at migration/qemu-file.c:523 #7 0x00007f3e03274cb2 in qemu_get_be32 (f=f@entry=0x7f3e05910f00) at migration/qemu-file.c:603 #8 0x00007f3e03271735 in colo_receive_message (f=0x7f3e05910f00, errp=errp@entry=0x7f3d62bfaa50) at migration/colo.c:215 #9 0x00007f3e0327250d in colo_wait_handle_message (errp=0x7f3d62bfaa48, checkpoint_request=<synthetic pointer>, f=<optimized out>) at migration/colo.c:546 #10 colo_process_incoming_thread (opaque=0x7f3e067245e0) at migration/colo.c:649 #11 0x00007f3e00cc1df3 in start_thread () from /lib64/libpthread.so.0 #12 0x00007f3dfc9c03ed in clone () from /lib64/libc.so.6 -- View this message in context: http://qemu.11.n7.nabble.com/COLO-failover-hang-tp473250.html Sent from the Developer mailing list archive at Nabble.com.