Re: When is "physical-device" created in xenstore?

[Ewan Mellor <ewan@xensource.com>]

On Tue, Sep 20, 2005 at 07:41:09PM +0800, Tian, Kevin wrote:

> If making following temp hack in XendDomainInfo.py:
> 
>              back = { 'type' : type,
>                       'params' : params,
>                       'frontend' : frontpath,
> -                     'frontend-id' : "%i" % self.domid }
> +                     'frontend-id' : "%i" % self.domid,
> +                    'physical-device' : "%li" % blkdev_name_to_number(params) }
>              xstransact.Write(backpath, back)
> 
> Then physical-device is created under backend and the communication can be
> setup. However this hard code definitely breaks existing logical
> behind. Should I do any specific configuration? From the Blkctl.py, it said
> that "phy" type doesn't require bind/unbind script, but I didn't find the
> place to add that item specifically. ;-(

Hi Kevin,

The key physical-device is created inside the block-phy script, as I think you
found.  This is called by xen-backend.agent, which in turn is called by the
Linux hotplug system (keying off the name 'xen-backend').  The file Blkctl.py
is completely unused, AFAICT, and should be removed.

The problems that you are having starting your device are probably down to a
broken or nonexistent installation of the hotplug system.  You should check
that first.  If your hotplug system is working, then maybe you are failing to
find xenstore-write.

HTH,

Ewan.