On 11/02/2009 03:40 PM, lir...@il.ibm.com wrote:
This series adds support for live migration without shared storage, means
copy the storage while migrating. It was tested with KVM. Supports 2 ways
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 allocated
data (user responsibility to verify that the same backend file reside
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 storage copy
(qemu) migrate -d blk inc tcp:0:4444 # for live migration with incremental
storage copy, storage is cow based.
I'd like to see the syntax generalized. For one, the guest may have
several disks; an install image cdrom might be available as an nfs image
but the main storage is local. Secondly, there can be several levels of
cow and we want to control which one we copy.
I'll leave the exact details to the qpeople, but if we can specify a
copy depth for each device, where 0=copy nothing, n=copy everything,
1=copy the last level (equivalent to -d blk inc) I think we'll have
covered everything.
--
Do not meddle in the internals of kernels, for they are subtle and quick to
panic.