Xen-нода падает с Kernel Panic

Привет.
Есть несколько серверов в разных ДЦ с одинаковыми инсталляциями CentOS 5.x 64bit + Xen 3.4.3
Ни с того ни с сего стали появляться падения с Kernel Panic (вывод ниже).

Посоветуйте, что делать и куда копаться?

Вот информация о системе
# xm info :
release : 2.6.18-274.3.1.el5xen
version : #1 SMP Tue Sep 6 20:57:11 EDT 2011
machine : x86_64
nr_cpus : 8
nr_nodes : 1
cores_per_socket : 4
threads_per_core : 2
cpu_mhz : 2533
hw_caps : bfebfbff:28100800:00000000:00000340:0098e3fd:00000000:00000001:00000000
virt_caps : hvm
total_memory : 32759
free_memory : 16822
node_to_cpu : node0:0-7
node_to_memory : node0:16822
xen_major : 3
xen_minor : 4
xen_extra : .3
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 : unavailable
cc_compiler : gcc version 4.1.2 20080704 (Red Hat 4.1.2-50)
cc_compile_by : root
cc_compile_domain : gitco.tld
cc_compile_date : Sun Jun 19 13:52:00 CEST 2011
xend_config_format : 4

Вот пример вывода ядра перед паднием:

Oct 4 16:46:00 server Unable to handle kernel NULL pointer dereference
Oct 4 16:46:00 server at 00000000000003c8 RIP:
Oct 4 16:46:00 server [<ffffffff88652383>] :bridge:__br_deliver+0xcd/0xfb
Oct 4 16:46:00 server PGD 1a8bd067
Oct 4 16:46:00 server PUD 132e9067
Oct 4 16:46:00 server PMD 0
Oct 4 16:46:00 server
Oct 4 16:46:00 server Oops: 0000 [1]
Oct 4 16:46:00 server SMP
Oct 4 16:46:00 server
Oct 4 16:46:00 server last sysfs file: /devices/xen-backend/vbd-2-768/statistics/wr_sect
Oct 4 16:46:00 server CPU 1
Oct 4 16:46:00 server
Oct 4 16:46:00 server Modules linked in:
Oct 4 16:46:00 server netconsole
Oct 4 16:46:00 server ebtable_filter
Oct 4 16:46:00 server ebtables
Oct 4 16:46:00 server tun
Oct 4 16:46:00 server bridge
Oct 4 16:46:00 server netloop
Oct 4 16:46:00 server netbk
Oct 4 16:46:00 server blktap
Oct 4 16:46:00 server blkbk
Oct 4 16:46:00 server ipt_REDIRECT
Oct 4 16:46:00 server ipt_owner
Oct 4 16:46:00 server ip_nat_ftp
Oct 4 16:46:00 server ip_conntrack_ftp
Oct 4 16:46:00 server xt_state
Oct 4 16:46:00 server xt_length
Oct 4 16:46:00 server ipt_ttl
Oct 4 16:46:00 server xt_tcpmss
Oct 4 16:46:00 server ipt_TCPMSS
Oct 4 16:46:00 server xt_multiport
Oct 4 16:46:00 server xt_limit
Oct 4 16:46:00 server ipt_LOG
Oct 4 16:46:00 server ipt_TOS
Oct 4 16:46:00 server ipt_tos
Oct 4 16:46:00 server ipt_REJECT
Oct 4 16:46:00 server iptable_filter
Oct 4 16:46:00 server iptable_nat
Oct 4 16:46:00 server ip_nat
Oct 4 16:46:00 server ip_conntrack
Oct 4 16:46:00 server nfnetlink
Oct 4 16:46:00 server ip_tables
Oct 4 16:46:00 server x_tables
Oct 4 16:46:00 server loop
Oct 4 16:46:00 server dm_mirror
Oct 4 16:46:00 server dm_multipath
Oct 4 16:46:00 server scsi_dh
Oct 4 16:46:00 server video
Oct 4 16:46:00 server backlight
Oct 4 16:46:00 server sbs
Oct 4 16:46:01 server power_meter
Oct 4 16:46:01 server hwmon
Oct 4 16:46:01 server i2c_ec
Oct 4 16:46:01 server dell_wmi
Oct 4 16:46:01 server wmi
Oct 4 16:46:01 server button
Oct 4 16:46:01 server battery
Oct 4 16:46:01 server asus_acpi
Oct 4 16:46:01 server ac
Oct 4 16:46:01 server parport_pc
Oct 4 16:46:01 server lp
Oct 4 16:46:01 server parport
Oct 4 16:46:01 server sr_mod
Oct 4 16:46:01 server cdrom
Oct 4 16:46:01 server sg
Oct 4 16:46:01 server snd_hda_intel
Oct 4 16:46:01 server snd_seq_dummy
Oct 4 16:46:01 server snd_seq_oss
Oct 4 16:46:01 server snd_seq_midi_event
Oct 4 16:46:01 server snd_seq
Oct 4 16:46:01 server snd_seq_device
Oct 4 16:46:01 server snd_pcm_oss
Oct 4 16:46:01 server snd_mixer_oss
Oct 4 16:46:01 server snd_pcm
Oct 4 16:46:01 server snd_timer
Oct 4 16:46:01 server snd_page_alloc
Oct 4 16:46:01 server tpm_tis
Oct 4 16:46:01 server snd_hwdep
Oct 4 16:46:01 server i2c_i801
Oct 4 16:46:01 server snd
Oct 4 16:46:01 server e1000e
Oct 4 16:46:01 server tpm
Oct 4 16:46:01 server serial_core
Oct 4 16:46:01 server soundcore
Oct 4 16:46:01 server i2c_core
Oct 4 16:46:01 server pcspkr
Oct 4 16:46:01 server serio_raw
Oct 4 16:46:01 server tpm_bios
Oct 4 16:46:01 server dm_raid45
Oct 4 16:46:01 server dm_message
Oct 4 16:46:01 server dm_region_hash
Oct 4 16:46:01 server dm_log
Oct 4 16:46:01 server dm_mod
Oct 4 16:46:01 server dm_mem_cache
Oct 4 16:46:01 server ahci
Oct 4 16:46:01 server libata
Oct 4 16:46:01 server shpchp
Oct 4 16:46:01 server megaraid_sas
Oct 4 16:46:01 server sd_mod
Oct 4 16:46:01 server scsi_mod
Oct 4 16:46:01 server ext3
Oct 4 16:46:01 server jbd
Oct 4 16:46:01 server uhci_hcd
Oct 4 16:46:01 server ohci_hcd
Oct 4 16:46:01 server ehci_hcd
Oct 4 16:46:01 server
Oct 4 16:46:01 server Pid: 26388, comm: qemu-dm Not tainted 2.6.18-274.3.1.el5xen #1
Oct 4 16:46:01 server RIP: e030:[<ffffffff88652383>]
Oct 4 16:46:01 server [<ffffffff88652383>] :bridge:__br_deliver+0xcd/0xfb
Oct 4 16:46:01 server RSP: e02b:ffff8800065d3b18 EFLAGS: 00010296
Oct 4 16:46:01 server RAX: 0000000000000000 RBX: ffff880034831000 RCX: ffff880009b95bc0
Oct 4 16:46:01 server RDX: ffffffff80000000 RSI: ffff880009b95bc0 RDI: ffff88003846be00
Oct 4 16:46:01 server RBP: ffff880037dfa500 R08: 0000000002000000 R09: ffffffff88652195
Oct 4 16:46:01 server R10: 0000000080000000 R11: ffffffff8853f9c0 R12: ffff880009b95c18
Oct 4 16:46:01 server R13: ffffffff80567f00 R14: ffff880037dfa000 R15: 0000000000000000
Oct 4 16:46:01 server FS: 00002ba775bc9bf0(0000) GS:ffffffff8062e080(0000) knlGS:0000000000000000
Oct 4 16:46:01 server CS: e033 DS: 0000 ES: 0000
Oct 4 16:46:01 server Process qemu-dm (pid: 26388, threadinfo ffff88003e064000, task ffff88001b614080)
Oct 4 16:46:01 server Stack:
Oct 4 16:46:01 server ffff880009b95bc0
Oct 4 16:46:01 server ffff880009b95bc0
Oct 4 16:46:01 server ffff880037dfa500
Oct 4 16:46:01 server ffffffff88651294
Oct 4 16:46:01 server
Oct 4 16:46:01 server ffff88001df131c0
Oct 4 16:46:01 server ffff880009b95bc0
Oct 4 16:46:01 server ffffffff808d3870
Oct 4 16:46:01 server ffffffff80424b93
Oct 4 16:46:01 server
Oct 4 16:46:01 server ffff880033474460
Oct 4 16:46:01 server ffff880009b95bc0
Oct 4 16:46:01 server
Oct 4 16:46:01 server Call Trace:
Oct 4 16:46:01 server <IRQ>
Oct 4 16:46:01 server [<ffffffff88651294>] :bridge:br_dev_xmit+0xc7/0xdb
Oct 4 16:46:01 server [<ffffffff80424b93>] dev_hard_start_xmit+0x1b7/0x28a
Oct 4 16:46:01 server [<ffffffff80230b81>] dev_queue_xmit+0x31f/0x3ef
Oct 4 16:46:01 server [<ffffffff80233073>] ip_output+0x29a/0x2dd
Oct 4 16:46:01 server [<ffffffff80441cb7>] ip_forward+0x24f/0x2bd
Oct 4 16:46:01 server [<ffffffff80236cdc>] ip_rcv+0x539/0x57c
Oct 4 16:46:01 server [<ffffffff80221590>] netif_receive_skb+0x495/0x4c4
Oct 4 16:46:01 server [<ffffffff88652efd>] :bridge:br_handle_frame_finish+0x1bc/0x1d3
Oct 4 16:46:01 server [<ffffffff88657123>] :bridge:br_nf_pre_routing_finish+0x2e9/0x2f8
Oct 4 16:46:02 server [<ffffffff88656e3a>] :bridge:br_nf_pre_routing_finish+0x0/0x2f8
Oct 4 16:46:02 server [<ffffffff80258542>] nf_hook_slow+0x58/0xbc
Oct 4 16:46:02 server [<ffffffff88656e3a>] :bridge:br_nf_pre_routing_finish+0x0/0x2f8
Oct 4 16:46:02 server [<ffffffff8028829d>] find_busiest_group+0x1db/0x44a
Oct 4 16:46:02 server [<ffffffff88657d20>] :bridge:br_nf_pre_routing+0x600/0x61c
Oct 4 16:46:02 server [<ffffffff802352d4>] nf_iterate+0x41/0x7d
Oct 4 16:46:02 server [<ffffffff88652d41>] :bridge:br_handle_frame_finish+0x0/0x1d3
Oct 4 16:46:02 server [<ffffffff80258542>] nf_hook_slow+0x58/0xbc
Oct 4 16:46:02 server [<ffffffff88652d41>] :bridge:br_handle_frame_finish+0x0/0x1d3
Oct 4 16:46:02 server [<ffffffff88653082>] :bridge:br_handle_frame+0x16e/0x1a4
Oct 4 16:46:02 server [<ffffffff802214a3>] netif_receive_skb+0x3a8/0x4c4
Oct 4 16:46:02 server [<ffffffff802488d3>] try_to_wake_up+0x392/0x3a4
Oct 4 16:46:02 server [<ffffffff802319a4>] process_backlog+0x9b/0x104
Oct 4 16:46:02 server [<ffffffff8020d0a1>] net_rx_action+0xb4/0x1c6
Oct 4 16:46:02 server [<ffffffff80212f06>] __do_softirq+0x8d/0x13b
Oct 4 16:46:02 server [<ffffffff8025fda4>] call_softirq+0x1c/0x278
Oct 4 16:46:02 server <EOI>
Oct 4 16:46:02 server [<ffffffff8026db69>] do_softirq+0x31/0x90
Oct 4 16:46:02 server [<ffffffff8024fc30>] netif_rx_ni+0x19/0x1d
Oct 4 16:46:02 server [<ffffffff8866d51d>] :tun:tun_chr_writev+0x3b4/0x402
Oct 4 16:46:02 server [<ffffffff8020bf28>] free_hot_cold_page+0x133/0x175
Oct 4 16:46:02 server [<ffffffff8866d585>] :tun:tun_chr_write+0x1a/0x1f
Oct 4 16:46:02 server [<ffffffff8021747d>] vfs_write+0xce/0x174
Oct 4 16:46:02 server [<ffffffff80217cc6>] sys_write+0x45/0x6e
Oct 4 16:46:02 server [<ffffffff8025f106>] system_call+0x86/0x8b
Oct 4 16:46:02 server [<ffffffff8025f080>] system_call+0x0/0x8b
Oct 4 16:46:02 server
Oct 4 16:46:02 server
Oct 4 16:46:02 server Code:
Oct 4 16:46:02 server 48
Oct 4 16:46:02 server 8b
Oct 4 16:46:02 server 80
Oct 4 16:46:02 server c8
Oct 4 16:46:02 server 03
Oct 4 16:46:02 server 00
Oct 4 16:46:02 server 00
Oct 4 16:46:02 server 48
Oct 4 16:46:02 server 85
Oct 4 16:46:02 server c0
Oct 4 16:46:02 server 74
Oct 4 16:46:02 server 1e
Oct 4 16:46:02 server 48
Oct 4 16:46:02 server 8b
Oct 4 16:46:02 server 50
Oct 4 16:46:02 server 38
Oct 4 16:46:02 server 48
Oct 4 16:46:02 server 8b
Oct 4 16:46:02 server 45
Oct 4 16:46:02 server 18
Oct 4 16:46:02 server
Oct 4 16:46:02 server RIP
Oct 4 16:46:02 server [<ffffffff88652383>] :bridge:__br_deliver+0xcd/0xfb
Oct 4 16:46:02 server RSP <ffff8800065d3b18>
Oct 4 16:46:02 server CR2: 00000000000003c8
Oct 4 16:46:02 server
Oct 4 16:46:02 server Kernel panic - not syncing: Fatal exception
Oct 4 16:46:02 server

Спасибо.