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
Regards,
Dan.
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