Hello everyone,

We have 5 HP BL460 Gen9 servers working as XEN hypervisors under SLES 12 SP1, every server hosts 4-5 fullvirt SLES 12 SP1 guests.
About 1 time in 2 months random DomU guest gets unresponsive, in xl list i see system state just as "------", i can ping the guest, but ssh/vnc is not responding. The only option to bring system back is to power off and restart it from virt-manager.

In system logs at that time i can see qemu-system-i386 segfaults:
Code:
[16312686.295207] IPv6: udp checksum is 0
[18570901.441606] qemu-system-i38[3619]: segfault at 0 ip 00007fcc3b3e1fae sp 00007ffeed8f5068 error 4 in libc-2.19.so[7fcc3b352000+19e000]
[18570901.527129] br0: port 3(vif1.0-emu) entered disabled state
This happens on all XEN hypervisors.
xl info:
Code:
xl info
host                   : MSK-HVX05
release                : 3.12.49-11-xen
version                : #1 SMP Wed Nov 11 20:52:43 UTC 2015 (8d714a0)
machine                : x86_64
nr_cpus                : 40
max_cpu_id             : 39
nr_nodes               : 2
cores_per_socket       : 10
threads_per_core       : 2
cpu_mhz                : 2297
hw_caps                : bfebfbff:2c100800:00000000:00007f00:77fefbff:00000000:00000021:000037ab
virt_caps              : hvm hvm_directio
total_memory           : 262015
free_memory            : 159893
sharing_freed_memory   : 0
sharing_used_memory    : 0
outstanding_claims     : 0
free_cpus              : 0
xen_major              : 4
xen_minor              : 5
xen_extra              : .1_12-2
xen_version            : 4.5.1_12-2
xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 
xen_scheduler          : credit
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          : 
xen_commandline        : dom0_mem=5785M,max:5785M
cc_compiler            : gcc (SUSE Linux) 4.8.5
cc_compile_by          : abuild
cc_compile_domain      : suse.de
cc_compile_date        : Thu Nov  5 14:42:08 UTC 2015
xend_config_format     : 4


I am trying to catch core dump, but i don't know, what do i need to get:
1) Core dump of domU kernel
2) Core dump of crashed qemu-system-i386 process on hypervisor

Please, give me some advice, what do i need to catch.