Re: [Libvir] [Libvirt] Proposal to add 3 functions for VBDs (Virtual Block Devices)

On Thu, Aug 24, 2006 at 12:51:58PM -0400, Daniel Veillard wrote: > On Thu, Aug 24, 2006 at 05:54:21PM +0200, Philippe Berthault wrote: > > I think that, instead of designate the backend domain by its id, it > > would be better to designate it by its name. > > This is because the id isn't fix, excepted for the domain-0. > > Right, providing a flexible and generic enough naming scheme is probably > the best, using strings is definitely better IMHO. Usually devices will > be associated to existing devices or files, which will be referenced by > names. If those resources doesn't exist as such or can't be named, it's > better to still build a naming scheme around the mechanism, for example: > > 'xen:vbd:0:1234' or 'xen:vif:2:0123' > > and using those names separates the API from the specifics, while allowing > some flexibility. This is just exposing xen specific attributes via the backdoor, rather than via an explicit API. The result is same - applications will become more dependant on particular hypervisor impementation details.

If we're going to expose block info & allow attach / detach, we should follow the data format already exposed for block devices in the XML: - device name - eg hda, xvda1, xvda1, etc - backing store - path to a file - type - phys / file - readonly - boolean - type - floppy, cdrom, disk