Re: [Qemu-devel] [Qemu-block] [PATCH COLO-Block v6 07/16] Add new block driver interface to connect/disconnect the remote target

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Wen Congyang (wency@cn.fujitsu.com) wrote:
> On 07/01/2015 03:01 AM, Dr. David Alan Gilbert wrote:
> > * Wen Congyang (wency@cn.fujitsu.com) wrote:
> >> On 06/27/2015 03:03 AM, Dr. David Alan Gilbert wrote:
> > 
> > <snip>
> > 
> >>> Ah, I hadn't realised you could do that; so do you just do:
> >>>
> >>> migrate_set_parameter colo on
> >>> migrate -d -b tcp:otherhhost:port
> >>>
> >>> How does the secondary know to feed that data straight into the disk without
> >>> recording all the old data into the hidden-disk ?
> >>
> >> hidden disk and active disk will be made empty when starting block replication.
> > 
> > Hmm, yes - I think I need to update to your current world; in the version
> > from the end of May, I get a 'error while loading state for instance 0x0 of device 'block''
> > if I try to use migrate -d -b 
> > (the bdrv_write fails)
> 
> Can you give me both primary and secondary qemu's command? I think the command line is wrong,
> and disk migration fails.
> 

Primary:

./try/bin/qemu-system-x86_64 -enable-kvm -nographic \
     -boot c -m 4096 -smp 4 -S \
     -name debug-threads=on -trace events=trace-file \
     -netdev tap,id=hn0,script=$PWD/ifup-prim,\
downscript=no,colo_script=$PWD/qemu/scripts/colo-proxy-script.sh,colo_nicname=em4 \
     -device e1000,mac=9c:da:4d:1c:b5:89,id=net-pci0,netdev=hn0 \
     -drive if=virtio,driver=quorum,read-pattern=fifo,no-connect=on,\
cache=none,aio=native,\
children.0.file.filename=./bugzilla.raw,\
children.0.driver=raw,\
children.1.file.driver=nbd,\
children.1.file.host=ibpair,\
children.1.file.port=8889,\
children.1.file.export=colo1,\
children.1.driver=replication,\
children.1.mode=primary,\
children.1.ignore-errors=on


Secondary:

./try/bin/qemu-system-x86_64 -enable-kvm -nographic \
     -boot c -m 4096 -smp 4 -S \
     -name debug-threads=on -trace events=trace-file \
     -netdev tap,id=hn0,script=$PWD/ifup-slave,\
downscript=no,colo_script=$PWD/qemu/scripts/colo-proxy-script.sh,colo_nicname=em4 \
     -device e1000,mac=9c:da:4d:1c:b5:89,id=net-pci0,netdev=hn0 \
     -drive if=none,driver=raw,file=bugzilla.raw,id=nbd_target1,cache=none,aio=native \
     -drive if=virtio,driver=replication,mode=secondary,export=colo1,throttling.bps-total-max=70000000,\
file.file.filename=/run/colo-active-disk.qcow2,\
file.driver=qcow2,\
file.backing_reference.drive_id=nbd_target1,\
file.backing_reference.hidden-disk.file.filename=/run/colo-hidden-disk.qcow2,\
file.backing_reference.hidden-disk.driver=qcow2,\
file.backing_reference.hidden-disk.allow-write-backing-file=on \
     -incoming tcp:0:8888


Thanks,

Dave

> >>>> If the user uses mirror job, we don't cancel the mirror job now.
> >>>
> >>> It would be good to get it to work with mirror, that seems preferred these
> >>> days to the old block migration.
> >>
> >> In normal migration, is mirror job created and cancelled by libvirt?
> > 
> > Yes, I think so; you should be able to turn on full logging on libvirt and
> > watch the qmp commands it sends.
> 
> Supporting mirror job in my TODO list now. But I think we should focus the basci function now.
> 
> Thanks
> Wen Congyang
> 
> > 
> > Dave
> > 
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > .
> > 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK