On Mon, Jan 19, 2009 at 07:20:07PM -0500, Mark Wagner wrote:
Daniel P. Berrange wrote:
On Mon, Jan 19, 2009 at 01:53:48PM +0100, Daniel Schwager wrote:
Hi Daniel,
Charles Duffy (thanks Charles !) told me how to fix libvirt for using the new "-incoming" API - yust replace "stdio" with "exec:cat" ..
Works like a charm, tested with FC9, libvirt.0.5.1-2 and KVM-83
Unfortunately things are not that simple. This will work for new KVM, but break for older KVM which only supports 'stdio:', 'file://' and 'tcp://' for incoming migration. There needs to be some kind of version / support check here to decide which syntax to use.
Daniel
So are there guidelines posted somewhere for the backwards compatibility that must be maintained ?
The code is written to work with all QEMU >= 0.8.2, which includes basically all KVM (bugs aside). In this case we've long supported the existing KVM migrate syntax and cannot break our existing users of it.
If you try to support every older version of each hypervisor / product you will quickly have a test matrix that will make it darn near impossible to actually release a new version of libvirt w/o a tremendously long test cycle.
This is why we have an extensive test suite to cover generation of command line arguments & explicitly test these kind of scenarios where one version changes the command line syntax. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|