Re: [Qemu-devel] qemu live migration error from 2.0 to 2.1

[Markus Armbruster]

William Dauchy <address@hidden> writes:

> On Tue, Aug 5, 2014 at 8:57 PM, Dr. David Alan Gilbert
> <address@hidden> wrote:
>> Can you confirm this is on the final 2.1 release (there was a fix that
>> went in just around rc5).
>
> for the receiver, I'm using 2.1
> # qemu-system-x86_64 --version
> QEMU emulator version 2.1.0, Copyright (c) 2003-2008 Fabrice Bellar
>
>
> for the sender side, here is the qmp result:
>
> (QEMU) query-version
> {   u'return': {   u'package': u'',
>                    u'qemu': {   u'major': 2, u'micro': 50, u'minor': 0}}}
>
>> What's your command line on both ends?
>
> the receiver:
>
> qemu-system-x86_64 -m 2048 -cpu host,level=9 -nodefconfig -nodefaults
> -nographic -readconfig /var/lib/qemu/VM_A/config -pidfile
> /var/lib/qemu/VM_A/pid -serial pty -D /var/lib/qemu/VM_A/log -d
> unimp,guest_errors -incoming tcp:0:32768
>
> /var/lib/qemu/VM_A/config:
> [name]
>   guest = "VM_A"
>   process = "VM_A"
>
> [chardev "compat_monitor0"]
>   backend = "socket"
>   path = "/var/lib/qemu/VM_A/sock"
>   server = "on"
>   wait = "off"
>
> [device]
>   driver = "virtio-balloon"
>
> [rtc]
>   base = "utc"
>
> [mon "compat_monitor0"]
>   mode = "control"
>   chardev = "compat_monitor0"
>   default = "on"
>
> [machine]
>   kernel = "/boot/bzImage"
>   append = "root=/dev/sda console=ttyS0 ro"
>   accel = "kvm"
>
> [device]
>   driver = "virtio-rng-pci"
>
> [device "scsi0"]
>   driver = "virtio-scsi-pci"
>   hotplug = "on"
>
> [...] vif config
>
> [...] disk config
>
> [smp-opts]
>   cpus = "2"
>   sockets = "1"
>   cores = "1"
>   threads = "1"
>   maxcpus = "12"
>
>
> the sender has the exact same command (without tcp receiver) and also
> the same config; I'm just issuing a migrate command through qmp.

Looks like you're not specifying a machine type.

If that's the case, your source machine uses the old QEMU's default
machine type, probably pc-i440fx-2.0, and your destination machine uses
the new default, probably pc-i440fx-2.1.

Migration requires identical machine types on source and destination.
If they differ, migration may work anyway (this is the very lucky case),
fail outright (lucky case), or it may succeed, then make the guest
misbehave or blow up on the destination, possibly after some delay.

Please try with 'type = "pc-i440fx-2.0"' in your '[machine]' section.