Re: XenServer virtual disks attach in wrong order

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

On Thu, 29 Mar 2012, Manuel Bouyer wrote:
> On Thu, Mar 29, 2012 at 04:45:02PM +0100, Stephen Borrill wrote:
> > I'm running a 6.0_BETA PV guest in XenServer and have added a second
> > virtual disk. In XenCenter this is shown as (approx):
> > pos name size device
> > 0 root 10GB  /dev/xvda
> > 1 test 1GB /dev/xvdb
> >
> > However, the 1GB (/dev/xvdb) disk is mapped to /dev/xbd0 and 10GB
> > (/dev/xvda) is mapped to /dev/xbd1.
> > xbd0 at xenbus0 id 51728: Xen Virtual Block Device Interface
> > xbd1 at xenbus0 id 51712: Xen Virtual Block Device Interface
> > [snip]
> > boot device: xbd0
> > root on xbd0a dumps on xbd0b
> >
> > I guess this is related to:
> > http://mail-index.netbsd.org/port-xen/2012/02/09/msg007127.html
> >
> > The id figures are 0xca10 and 0xca00 respectively.
>
> yes, that's the same problem. I guess it's because XenCenter puts the
> VBD configs in reverse order ...

Indeed:
[root@xenserver2 ~]# xenstore-ls /local/domain/38/device/vbd
51728 = ""
 backend = "/local/domain/0/backend/vbd/38/51728"
 protocol = "x86_64-abi"
 state = "4"
 backend-id = "0"
 device-type = "disk"
 virtual-device = "51728"
 ring-ref = "511"
 event-channel = "8"
51712 = ""
 backend = "/local/domain/0/backend/vbd/38/51712"
 protocol = "x86_64-abi"
 state = "4"
 backend-id = "0"
 device-type = "disk"
 virtual-device = "51712"
 ring-ref = "510"
 event-channel = "9"

Any reason not to sort on id in xenbus_probe_device_type()?

--
Stephen