Bug 445504

Can you provide the console output from the crash?

Not much interesting from my POV in log:

Before the first crash:

May  7 09:37:30 dhcp-lab-198 kernel: virbr0: port 7(vif13.0) entering disabled state
May  7 09:37:30 dhcp-lab-198 kernel: device vif13.0 left promiscuous mode
May  7 09:37:30 dhcp-lab-198 kernel: virbr0: port 7(vif13.0) entering disabled state
May  7 09:37:31 dhcp-lab-198 logger: /etc/xen/scripts/blktap: xenstore-read
/local/domain/13/vm failed.
May  7 09:37:31 dhcp-lab-198 logger: /etc/xen/scripts/blktap:
/etc/xen/scripts/blktap failed; error detected.
May  7 09:38:19 dhcp-lab-198 kernel: tap tap-14-51712: 2 getting info
May  7 09:38:19 dhcp-lab-198 kernel: device vif14.0 entered promiscuous mode
May  7 09:38:19 dhcp-lab-198 kernel: ADDRCONF(NETDEV_UP): vif14.0: link is not ready
May  7 09:38:20 dhcp-lab-198 kernel: ADDRCONF(NETDEV_CHANGE): vif14.0: link
becomes ready
May  7 09:38:20 dhcp-lab-198 kernel: blktap: ring-ref 522, event-channel 9,
protocol 1 (x86_32-abi)
May  7 09:38:20 dhcp-lab-198 kernel: virbr0: port 7(vif14.0) entering listening
state
May  7 09:38:35 dhcp-lab-198 kernel: virbr0: port 7(vif14.0) entering learning state
May  7 09:38:50 dhcp-lab-198 kernel: virbr0: topology change detected, propagating
May  7 09:38:50 dhcp-lab-198 kernel: virbr0: port 7(vif14.0) entering forwarding
state

...

then it worked for 10 minutes, I issued the third guest and it restarted/crashed.

Before second crash:

May  7 10:25:45 dhcp-lab-198 kernel: device tap5 entered promiscuous mode
May  7 10:25:45 dhcp-lab-198 kernel: xenbr0: port 7(tap5) entering learning state
May  7 10:25:45 dhcp-lab-198 kernel: xenbr0: topology change detected, propagating
May  7 10:25:45 dhcp-lab-198 kernel: xenbr0: port 7(tap5) entering forwarding state
May  7 10:25:46 dhcp-lab-198 kernel: device vif7.0 entered promiscuous mode

<< immediate crash here

Attaching /var/log/xen/xend.log and /var/log/xen/xend.log.1, interesting seems
to be the end of $NAME.1 and the beginning of $NAME.

I am not able to provide output right after the crash because it simply
restarted. If you are aware of some place where is output from console
redirected let me know.

Created attachment 304961 [details]
xend.log

Created attachment 304962 [details]
xend.log old one

Sorry for not being clear. Can you run with serial console and capture that
output? That will show us the fault/panic info we need. Also is this on any
specific hardware? How much memory is on the system and how much are you giving
to each guest?

Thanks

Nothing special: Dell Precision 490, dual 64bit Xeon, 2 GB memory; 512 MB per
each guest. I am not able to reproduce it again but was able to do so the week
before.

Let's re-open it when it crashes again but for now...

Thanks for you time, Bill.

Ok, thanks.

Umm, I've been hit by this again when mangling with several guests... Could you
please point me or guide how to set up serial console?

The thing is that when it crasher it immediately restarts so I am unable to
catch any error msg, if any's there. 

Is it even possible to have the Dom0 shut down but hypervisor running and
possibly providing the error output? The crashes are irregular but often so I
can catch it someday. 

In the grub configuration for the "kernel" line (which loads xen.gz) you usually
add:
  console=com1 com1=115200,8n1
then on the next module line, where the dom 0 kernel gets loaded, you add
 console=ttyS0,115200

Then you need a serial cable to the box from another system ans
use the ttywatch program to monitor it.

Can't provide more data; never been hit by this for a long time. Thanks for your
time a nice guidance, Bill.