Re: [libvirt] [PATCH 2/2] add default migrate uri in definition file

Hi Daniel, On Tue, 2014-04-15 at 12:04 +0100, Daniel P. Berrange wrote: > On Tue, Apr 15, 2014 at 06:31:09PM +0800, Chen Fan wrote: > > Current virsh migrate command require specfying migration URI with > > command option. > > > > Here is current step. > > 1) If user specifies --migrateuri on virsh migrate command, then the command > > transfers the data to specified host. > > 2) If --migrateuri is not specified, the command transfers the data to host > > whose name is resolved by DNS or /etc/hosts. > > > > but we are able to use virsh migrate command more usefull. > > User can specify a constant destination by definition file. > > if user want to specify other temporary destination, command option > > is good for it.

> > IMHO the idea of storing the 'migration_uri' parameter in a configuration > file is just plain wrong. This value is inherantly associated with the > host that you're migrating to. So if you set 'migration_uri' to one host > in the config, but then invoke virDomainMigrate with a virConnectPtr that > is associated with a different host, this just crashes and burns. how about add a optional 'migrate_uri'(or 'data_migrate_uri') in libvirtd.conf as secondary network interface? if so, when user add a new NIC in host A, then user can store this NIC address to 'migrate_uri' parameter in the configuration file, then when doing migration from other host B to this host A, we can get the 'migrate_uri' address in host A and pass this uri back to host B as the new 'uri_out' value at domainMigratePrepare3Params(). then we don't need to change any existing APIs. and the new NIC used to transfer migrate data will be more useful.