Re: [Qemu-devel] [PATCH COLO-BLOCK v7 00/17] Block replication for continuous checkpoints

[Wen Congyang]

At 2015/7/9 21:40, Dr. David Alan Gilbert Wrote:
> * Wen Congyang (address@hidden) wrote:
> > On 07/09/2015 06:37 PM, Dr. David Alan Gilbert wrote:
> > > * Wen Congyang (address@hidden) wrote:
> > > > On 07/09/2015 05:16 PM, Dr. David Alan Gilbert wrote:
> > > > > * Wen Congyang (address@hidden) wrote:
> > > > >
> > > > > > > > I have sent the v8. But the usage is not changed. You can setup the environment 
> > > > > > > > according to the wiki.
> > > > > > > > When we open nbd client, we need to connect to the nbd server. So I introduce a 
> > > > > > > > new command child_add to add NBD client
> > > > > > > > as a quorum child when the nbd server is ready.
> > > > > > > >
> > > > > > > > The nbd server is ready after you run the following command:
> > > > > > > > nbd_server_start 0:6262 # the secondary qemu will listen to host:port
> > > > > > > > nbd_server_add -w mc1   # the NBD server will know this disk is used as NBD 
> > > > > > > > server. The export name is its id wc1.
> > > > > > > >                          # -w means we allow to write to this disk.
> > > > > > > >
> > > > > > > > Then you can run the following command in the primary qemu:
> > > > > > > > child_add disk1 
> > > > > > > > child.driver=replication,child.mode=primary,child.file.host=127.0.0.1,child.file.port=6262,child.file.export=mc1,child.file.driver=nbd,child.ignore-errors=on
> > > > > > > >
> > > > > > > > After this monitor command, nbd client has connected to the nbd server.
> > > > > > >
> > > > > > > Ah! The 'child.file.export=mc1' wasn't there previously; I see Yang added that 
> > > > > > > to the wiki yesterday;
> > > > > > > that probably explains the problem that we've been having.
> > > > > >
> > > > > > Sorry for this mistake.
> > > > >
> > > > > OK, so this is working for me (with the 7.2 world).   What isn't working in 
> > > > > this setup is migrate -b, I get:
> > > > >
> > > > > (qemu) Receiving block device images
> > > > > Error unknown block device disk1
> > > > > qemu-system-x86_64: error while loading state section id 1(block)
> > > > > qemu-system-x86_64: load of migration failed: Invalid argument
> > > > >
> > > > > Can you explain the id=disk1 on the master side?
> > > >
> > > > Can you give me the command line? I think the id in primary and secondary qemu 
> > > > is not same.
> > >
> > > Sure, 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 \
> > >       -device virtio-rng-pci \
> > >       -drive if=virtio,id=disk1,driver=quorum,read-pattern=fifo,\
> >
> > If you want to use block migration, set the id to colo1
>
> OK, does it make sense to always make it colo1 rather than having the 'disk1' 
> and 'colo1' names?

You can use anyone. The export name must be the secondary disk's id.

Thanks
Wen Congyang

> > > cache=none,aio=native,\
> > > children.0.file.filename=./bugzilla.raw,\
> > > children.0.driver=raw
> > >
> > > Sure, secondary:
> > >
> > > TMPDISKS=/run
> > > qemu-img create -f qcow2 $TMPDISKS/colo-hidden-disk.qcow2 40G
> > > qemu-img create -f qcow2 $TMPDISKS/colo-active-disk.qcow2 40G
> > >
> > > ./try/bin/qemu-system-x86_64 -enable-kvm -nographic \
> > >       -boot c -m 4096 -smp 4 -S \
> > >       -name debug-threads=on -trace events=trace-file \
> > >       -netdev tap,id=hn0,script=$PWD/ifup-slave,\
> > > downscript=no,colo_script=$PWD/qemu/scripts/colo-proxy-script.sh,colo_nicname=em4
> > >  \
> > >       -device e1000,mac=9c:da:4d:1c:b5:89,id=net-pci0,netdev=hn0 \
> > >       -device virtio-rng-pci \
> > >       -drive 
> > > if=none,driver=raw,file=/home/localvms/bugzilla.raw,id=colo1,cache=none,aio=native
> > >  \
> > >       -drive 
> > > if=virtio,driver=replication,mode=secondary,export=colo1,throttling.bps-total-max=70000000,\
> > > file.file.filename=$TMPDISKS/colo-active-disk.qcow2,\
> > > file.driver=qcow2,\
> > > file.backing.file.filename=$TMPDISKS/colo-hidden-disk.qcow2,\
> > > file.backing.driver=qcow2,\
> > > file.backing.backing.backing_reference=colo1,\
> > > file.backing.allow-write-backing-file=on \
> > >       -incoming tcp:0:8888
> > >
> > >
> > > Secondary:
> > >     nbd_server_start :8889
> > >     nbd_server_add -w colo1
> > >
> > > primary:
> > >
> > > child_add disk1 
> > > child.driver=replication,child.mode=primary,child.file.host=ibpair,child.file.port=8889,child.file.export=colo1,child.file.driver=nbd,child.ignore-errors=on
> >
> > here, it is child_add colo1 ....
> >
> > > (qemu) migrate_set_capability colo on
> > > (qemu) migrate -d -b tcp:ibpair:8888
> > >
> > >
> > > note the 'id=disk1' in the primary is shown in your wiki.
> >
> > IIRC, the default id is diskx, x is 1, 2, 3...
>
> OK, using the colo1 in both those places that works (this is in the 7.2 world)
> and the RAM disk size now doesn't grow in the -b block migrate.
>
> Dave
>
> > Thanks
> > Wen Congyang
> >
> > > Dave
> > >
> > >   Thanks
> > > > Wen Congyang
> > > >
> > > > > Dave
> > > > >
> > > > > > Thanks
> > > > > > Wen Congyang
> > > > > >
> > > > > > > Dave
> > > > > > >
> > > > > > > > Thanks
> > > > > > > > Wen Congyang
> > > > > > > >
> > > > > > > > > - Michael
> > > > > > > > >
> > > > > > > > > .
> > > > > > > --
> > > > > > > Dr. David Alan Gilbert / address@hidden / Manchester, UK
> > > > > > > .
> > > > > --
> > > > > Dr. David Alan Gilbert / address@hidden / Manchester, UK
> > > > > .
> > > --
> > > Dr. David Alan Gilbert / address@hidden / Manchester, UK
> > > .
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK