RE: Hotplug scripts not working... xen/ia64 domUstopped working

[David F Barrera <dfbp@us.ibm.com>]

Different problem. Something changed the order of my drives (hotplug?),
so now /dev/sdc7 is what before had been /dev/sdb7. 

/tmp/log:

xenstore-read: couldn't read path backend/vbd/2/2072/physical-device
stat: cannot stat `/dev/sdb8': No such file or directory
stat: cannot stat `/dev/sdb8': No such file or directory
+ PATH=/etc/xen/scripts:/bin:/sbin:/usr/sbin:/usr/bin
+ case "$XENBUS_TYPE" in
+ /etc/xen/scripts/block add
xenstore-read: couldn't read path backend/vif/2/0/ip
xenstore-read: couldn't read path backend/vif/2/0/bridge
+ PATH=/etc/xen/scripts:/bin:/sbin:/usr/sbin:/usr/bin
+ case "$XENBUS_TYPE" in
+ '[' -n '' ']'
+ case "$ACTION" in
+ case "$ACTION" in
xenstore-read: couldn't read path backend/vbd/2/2071/physical-device
+ case "$ACTION" in
stat: cannot stat `/dev/sdb7': No such file or directory
stat: cannot stat `/dev/sdb7': No such file or directory
+ case "$ACTION" in


On Fri, 2005-12-02 at 13:26 -0800, Magenheimer, Dan (HP Labs Fort
Collins) wrote:
> To see if the same workaround works for you that worked for
> me: edit /etc/hotplug/xen-backend.agent.  Add a -x at the
> end of the first line.  Insert a line between the first
> and second line with:
> exec 2>>/tmp/log
> 
> Then try again.  Though our messages are different, this
> changed timing enough for my problem to go away so it might
> be worth a try.
> 
> Dan 
> 
> > -----Original Message-----
> > From: David F Barrera [mailto:dfbp@us.ibm.com] 
> > Sent: Friday, December 02, 2005 2:22 PM
> > To: Magenheimer, Dan (HP Labs Fort Collins)
> > Cc: Ewan Mellor; xen-devel
> > Subject: RE: [Xen-devel] Hotplug scripts not working... 
> > xen/ia64 domUstopped working
> > 
> > I wonder if what I am seeing is the same problem described in this
> > thread. I am unable to create domUs on an x86_64 box, 
> > something which I
> > had been able to do even this morning:
> > 
> > VmError: Device 2070 (vbd) could not be connected. Backend device not
> > found.
> > 
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:119) Waiting 
> > for devices
> > vif.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:125) Waiting for 0.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:398)
> > hotplugStatusCallback /local/domain/0/backend/vif/1/0/hotplug-status.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:398)
> > hotplugStatusCallback /local/domain/0/backend/vif/1/0/hotplug-status.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:415)
> > hotplugStatusCallback 1.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:119) Waiting 
> > for devices
> > usb.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:119) Waiting 
> > for devices
> > vbd.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:125) Waiting for 2070.
> > [2005-12-02 15:11:25 xend] DEBUG (DevController:398)
> > hotplugStatusCallback /local/domain/0/backend/vbd/1/2070/hotplug-
> > status.[2005-12-02 15:11:25 xend] DEBUG (DevController:415)
> > hotplugStatusCallback 3.
> > [2005-12-02 15:11:25 xend] ERROR (SrvBase:87) Request wait_for_devices
> > failed.
> > Traceback (most recent call last):
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/web/SrvBase.py",
> >  line 85,
> > in perform
> >     return op_method(op, req)
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/xend/server/SrvD
> > omain.py",
> > line 72, in op_wait_for_devices
> >     return self.dom.waitForDevices()
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/xend/XendDomainInfo.py",
> > line 1276, in waitForDevices
> >     self.waitForDevices_(c)
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/xend/XendDomainInfo.py",
> > line 923, in waitForDevices_
> >     return self.getDeviceController(deviceClass).waitForDevices()
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/xend/server/DevC
> > ontroller.py", line 121, in waitForDevices
> >     return map(self.waitForDevice, self.deviceIDs())
> >   File "/tmp/xen-
> > unstable.hg/dist/install/usr/lib64/python/xen/xend/server/DevC
> > ontroller.py", line 137, in waitForDevice
> >     raise VmError("Device %s (%s) could not be connected. "
> > VmError: Device 2070 (vbd) could not be connected. Backend device not
> > found.
> > 
> > 
> > On Fri, 2005-12-02 at 12:40 -0800, Magenheimer, Dan (HP Labs Fort
> > Collins) wrote:
> > > > Anyway, I'd be inclined to try the new changesets (not yet 
> > > > pushed to the public
> > > > tree) and see if that improves things. 
> > > 
> > > Same problem and same workaround on tip (8169).  Please
> > > email when your new changesets get pushed and I will
> > > try them.
> > > 
> > > > > My /etc/xen/xmdefconfig is very short:
> > > > > kernel = "/tmp/xenlinux"
> > > > > memory = 256
> > > > > nics=0
> > > > > disk = ['phy:loop0,hda1,w']  # <-change to w!
> > > > > 
> > > > > and after a fresh boot, I am simply doing:
> > > > > 
> > > > > # lomount -t ext2 -diskimage /var/xen/hda /mnt
> > > > > # xend start
> > > > > # xm create
> > > > > 
> > > > > I can see how it could be interpreted that loop0 is
> > > > > being used both by domain0 and the newly created domain,
> > > > > but isn't this a common use model?
> > > > 
> > > > Only if you want to corrupt your filesystem!  Writing to that 
> > > > file via /mnt
> > > > in dom0 and via /dev/hda1 in the guest ought to corrupt your 
> > > > fs nicely.
> > > 
> > > Not as long as the image is only used from domU, correct?
> > > 
> > > What is the proper use model?  As I noted previously,
> > > disk = ['file:/var/xen/hda,hda1,w'] results in a Linux
> > > error message ("UDF-fs: No VRS found"... and, no, I do
> > > not have any CD's in /etc/fstab!).  Am I spelling
> > > this xmdefconfig entry incorrectly?  Or is there
> > > a better way to use a disk-in-a-file as root disk for
> > > a guest domain?
> > > 
> > > Thanks,
> > > Dan
> > > 
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel@lists.xensource.com
> > > http://lists.xensource.com/xen-devel
> > > 
> > -- 
> > Regards,
> > 
> > David F Barrera
> > Linux Technology Center
> > Systems and Technology Group, IBM
> > 
> > "The wisest men follow their own direction. "
> >                                                         Euripides
> > 
> > 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
> 
-- 
Regards,

David F Barrera
Linux Technology Center
Systems and Technology Group, IBM

"The wisest men follow their own direction. "
                                                        Euripides