On 7 sept. 2009, at 11:24, lirans@xxxxxxxxxx wrote:
This series adds support for live migration without shared storage,
copy the storage while migrating. It was tested with KVM. Supports 2
to replicate the storage during migration:
1. Complete copy of storage to destination
2. Assuming the storage is cow based, copy only the allocated
data, time of the migration will be linear with the amount of
data (user responsibility to verify that the same backend file
on src and destination).
Live migration will work as follows:
(qemu) migrate -d tcp:0:4444 # for ordinary live migration
(qemu) migrate -d blk tcp:0:4444 # for live migration with complete
(qemu) migrate -d blk inc tcp:0:4444 # for live migration with
incremental storage copy, storage is cow based.
The patches are against git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git
I'm trying blk migration (not incremental) between two machines
connected over Gigabit ethernet.
The transfer is quite slow (about 2 MB/s over the wire).
While the load on the sending end is low (vmstat says ~2000 blocks in/
sec, and top says ~1% in io wait), on the receiving end I see almost
40% CPU in io wait, kjournald takes 20% of the CPU and vmstat reports
~14000 blocks out/sec.
Hosts are running Debian Lenny (2.6.26 32 bits), kvm-87 + your patches.
The guest is also running Debian Lenny and is idle io wise. I tried
with both idle and full cpu utilization, it doesn't change anything.
Pierre Riteau -- http://perso.univ-rennes1.fr/pierre.riteau/