Re: [Xen-devel] XenStore management with driver domains.

[Daniel Stodden <daniel.stodden@xxxxxxxxxx>]

On Mon, 2010-01-18 at 17:24 -0500, Justin T. Gibbs wrote:
> I've been experimenting with serving block storage between DomUs.
> I can dynamically attach storage, transfer data to my hearts content,
> but dynamic detach is providing some trouble.  Both the front and
> backend drivers detach cleanly, but the XenStore data for the
> attachment persists, preventing the same storage object from
> being attached again.
> 
> After tracing through Xend and the hotplug scripts, it seems that
> the current framework assumes backend teardown will occur in Dom0.
> For example, xen-hotplug-cleanup, which is invoked when the backend
> device instance is removed, removes the following paths from the
> xenstore:
> 
>    /local/domain/<front domid>/device/<type>/<devid>
>    /local/domain/<back domid>/backend/<type>/<front domid>/<devid>
>    /local/domain/<back domid>/error/backend/<type>/<front domid>/<devid>
>    /vm/<front uuid>/device/<type>/<devid>

While you're cleaning up: Do you consider relative paths? 

I think fully qualified names such /local/domain/%d/device/vbd/%d/%d is
always wrong. Try using "device/vbd/%d/%d" instead.

I also think it I've seen this make an unwelcome difference in
permission checks for updates issued by domUs in the past. But this
information may be outdated.

Daniel



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel