On Sun, Apr 13, 2008 at 09:28:59AM +0100, Richard W.M. Jones wrote: > > What would be really useful is to allow paths (eg. to file-backed > block devices) to be relative in a useful way. This would let you > have the domain XML configuration file & the block device files sit > next to each other to give a machine description: > > mydomain.hda.img > mydomain.xml # refers to <source file="mydomain.hda.img"> > > This isn't possible at the moment as far as I can tell, which means > you need to know which directory the files are located in, and you > can't move them around. Having relative paths to disk files in the XML isn't useful because the drivers make no guarentees about where the XML files will be stored - if indeed they're stored at all. Full-qualified paths to disks are the only sensible option for domain XML IMHO. > [As an aside, at present the QEMU driver makes no attempt to check > that the source file is an absolute path, it just passes whatever it > finds to the '-hdc' argument to qemu.] > > For the command: > > virsh define mydomain.xml > > One implementation would be to have virsh rewriting paths, but that > requires special knowledge of the XML format in virsh so I don't think > it's a workable idea. Another would be to allow virsh to supply a > 'base URI' (basically, the current directory) to the > virDomainDefineXML call. > > Any thoughts? I think this is mixing up two concepts really - the domain XML is used to represent a specific instantiation of a domain and as such it should fully specify things like paths. The use case of keeping disk images & XML alongside each other is really in the realms of appliance images. The virt-image tool provides a format for describing appliances and does support having relative paths. It then turns this into the domain XML for the specific instantiation using a fully qualfied path. Dan. -- |: Red Hat, Engineering, Boston -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 :| -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list