Re: [Qemu-devel] live migration between different qemu versions

[Alexey <alukardd@alukardd.org>]

Hello,

On 2016-01-12 12:19, Dr. David Alan Gilbert wrote:
> * Alexey (alukardd@alukardd.org) wrote:
>> Hi David.
>> 
>> On 2016-01-11 22:51, Dr. David Alan Gilbert wrote:
>> >* Alexey (alukardd@alukardd.org) wrote:
>> >>Hello.
>> >
>> >Hi,
>> >
>> >>I have two servers between which I need have live migration.
>> >>
>> >>First server have QEMU emulator version 2.3.0
>> >>Second server have QEMU emulator version 2.5.0
>> >>
>> >>Migration command look like this:
>> >>/usr/bin/virsh migrate --live DOMAIN_NAME --migrateuri
>> >>tcp://second.server
>> >>qemu+ssh://second.server/system --verbose
>> >>
>> >>I got next error on console:
>> >>error: operation failed: migration job: unexpectedly failed
>> >>
>> >>And next error in log on second server:
>> >>2016-01-11T15:07:12.888647Z qemu-system-x86_64: Length too large:
>> >>/rom@genroms/efi-virtio.rom: 0x32000 > 0x2d000: Invalid argument
>> >>2016-01-11T15:07:12.888685Z qemu-system-x86_64: error while loading
>> >>state
>> >>for instance 0x0 of device 'ram'
>> >>2016-01-11T15:07:12.889733Z qemu-system-x86_64: load of migration
>> >>failed:
>> >>Invalid argument
>> >>
>> >>In my libvirt domain I have option <rom bar="off"/>.
>> >>
>> >>I need to do a live migration in any possible way. How can I do this
>> >>one?
>> 
>> >Is the efi-virtio ROM that you're using on the two versions the same
>> >identical size?
> 
>> No, I have different efi-virtio.rom files, and I try to find a way 
>> which
>> allows me not to copy the same efi-virtio.rom to all servers.
> 
> Right, the error does look like it's just complaining about the ROM 
> size:
> 
>   2016-01-11T15:07:12.888647Z qemu-system-x86_64: Length too large:
>   /rom@genroms/efi-virtio.rom: 0x32000 > 0x2d000: Invalid argument
> 
> It copes with small variations, but as soon as it flips over a 4K (?)
> boundary then it has nowhere to put the extra data coming from the
> larger ROM.
old server with qemu 2.3.0:
-rw-r--r-- 1 root root 203264 Nov 21  2014 
/usr/lib/ipxe/qemu/efi-virtio.rom

new server with qemu 2.5.0:
-rw-r--r-- 1 root root 184320 Oct 19  2014 
/usr/lib/ipxe/qemu/efi-virtio.rom

See, that destination server has smaller rom than source.
I interested in way which I could do live migration between different 
ROMs.
Also I interested in migration in both side: from old to new and from 
new to old.


>> >Also, can you post the commandline that you're using please.
>> I already done this in my first email: virsh migrate...
>> >>/usr/bin/virsh migrate --live DOMAIN_NAME --migrateuri
>> >>tcp://second.server
>> >>qemu+ssh://second.server/system --verbose
> Do you mean running domain command line?
> I meant for the QEMU itself; but if we've already found the ROMs are
> different sizes, lets fix that first and see how you go.
Do you mean command line of running domain?

qemu-system-x86_64 -enable-kvm -name 208664-73 -S -machine 
pc-i440fx-1.7,accel=kvm,usb=off -cpu 
kvm64,+lahf_lm,+popcnt,+sse4.2,+sse4.1,+ssse3,+ss,-mca,-mce -m 1024 
-realtime mlock=off -smp 4,sockets=4,cores=1,threads=1 -uuid 
08cf6bf2-a701-4a00-a0cb-4ecbe514c3d7 -no-user-config -nodefaults 
-chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/208664-73.monitor,server,nowait 
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc 
-no-shutdown -boot strict=on -device 
piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device 
virtio-scsi-pci,id=scsi0,num_queues=4,bus=pci.0,addr=0x4 -device 
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x6 -drive 
file=/dev/disk/vbd/208664-73,if=none,id=drive-scsi0-0-0-0,format=raw,cache=none,discard=unmap,aio=native 
-device 
scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=2 
-netdev tap,fd=53,id=hostnet0,vhost=on,vhostfd=54 -device 
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:00:40:b9,bus=pci.0,addr=0x3,rombar=0 
-chardev pty,id=charserial0 -device 
isa-serial,chardev=charserial0,id=serial0 -chardev 
socket,id=charchannel0,path=/var/lib/libvirt/qemu/208664-73.agent,server,nowait 
-device 
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 
-device usb-mouse,id=input0 -device usb-kbd,id=input1 -vnc 
[::]:12,password -device VGA,id=video0,vgamem_mb=16,bus=pci.0,addr=0x2 
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5 -object 
rng-random,id=objrng0,filename=/dev/random -device 
virtio-rng-pci,rng=objrng0,id=rng0,max-bytes=1024,period=2000,bus=pci.0,addr=0x7 
-msg timestamp=on

> 
> Dave
> 
>> 
>> Regards,
>> Alexey Mochkin.
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK