Re: [libvirt-users] Difference between function Migrate and Migrate2

On 06/10/2011 07:09 PM, Abhishek Gupta wrote: virDomainMigrate2 is the newer API with more features. Per the comments in libvirt.c: * virDomainMigrate: * @domain: a domain object * @dconn: destination host (a connection object) * @flags: flags * @dname: (optional) rename domain to this at destination * @uri: (optional) dest hostname/URI as seen from the source host * @bandwidth: (optional) specify migration bandwidth limit in Mbps * virDomainMigrate2: * @domain: a domain object * @dconn: destination host (a connection object) * @flags: flags * @dxml: (optional) XML config for launching guest on target * @dname: (optional) rename domain to this at destination * @uri: (optional) dest hostname/URI as seen from the source host * @bandwidth: (optional) specify migration bandwidth limit in Mbps the biggest difference is the new @dxml parameter, which allows you to make changes in the destination by passing in compatible xml to the host for hypervisors that know how to compare two xml images (as of 0.9.2, this is pretty much just the qemu hypervisor for kvm guests, but more may be added later). For example, only virDomainMigrate2 can let you update which host resource is used for a particular guest network interface, so that source and destination host no longer need have exactly the same names for host resources. But if you plan on passing NULL for dxml (implying no changes needed), then the simpler API is probably sufficient. -- Eric Blake eblake(a)redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org