On Thursday, October 15, 2015 03:30:01 PM hw wrote: > Hi, > > I have a xen host with some HV guests which becomes unreachable via > the network after apparently random amount of times. I have already > switched the network card to see if that would make a difference, > and with the card currently installed, it worked fine for over 20 days > until it become unreachable again. Before switching the network card, > it would run a week or two before becoming unreachable. The previous > card was the on-board BCM5764M which uses the tg3 driver. > > There are messages like this in the log file: > > > Oct 14 20:58:02 moonflo kernel: ------------[ cut here ]------------ > Oct 14 20:58:02 moonflo kernel: WARNING: CPU: 10 PID: 0 at > net/sched/sch_generic.c:303 dev_watchdog+0x259/0x270() Oct 14 20:58:02 > moonflo kernel: NETDEV WATCHDOG: enp55s4 (r8169): transmit queue 0 timed > out Oct 14 20:58:02 moonflo kernel: Modules linked in: arc4 ecb md4 hmac > nls_utf8 cifs fscache xt_physdev br_netfilter iptable_filter ip_tables > xen_pciback xen_gntalloc xen_gntdev bridge stp llc zfs(PO) nouveau > snd_hda_codec_realtek snd_hda_codec_generic zunicode(PO) zavl(PO) > zcommon(PO) znvpair(PO) spl(O) zlib_deflate video backlight drm_kms_helper > ttm snd_hda_intel snd_hda_controller snd_hda_codec snd_pcm snd_timer snd > soundcore r8169 mii xts aesni_intel glue_helper lrw gf128mul ablk_helper > cryptd aes_x86_64 sha256_generic hid_generic usbhid uhci_hcd usb_storage > ehci_pci ehci_hcd usbcore usb_common Oct 14 20:58:02 moonflo kernel: CPU: > 10 PID: 0 Comm: swapper/10 Tainted: P O 4.0.5-gentoo #3 Oct 14 > 20:58:02 moonflo kernel: Hardware name: Hewlett-Packard HP Z800 > Workstation/0AECh, BIOS 786G5 v03.57 07/15/2013 Oct 14 20:58:02 moonflo > kernel: ffffffff8175a77d ffff880124d43d98 ffffffff814da8d8 > 0000000000000001 Oct 14 20:58:02 moonflo kernel: ffff880124d43de8 > ffff880124d43dd8 ffffffff81088850 ffff880124d43dd8 Oct 14 20:58:02 moonflo > kernel: 0000000000000000 ffff8800d45f2000 0000000000000001 > ffff8800d5294880 Oct 14 20:58:02 moonflo kernel: Call Trace: > Oct 14 20:58:02 moonflo kernel: <IRQ> [<ffffffff814da8d8>] > dump_stack+0x45/0x57 Oct 14 20:58:02 moonflo kernel: [<ffffffff81088850>] > warn_slowpath_common+0x80/0xc0 Oct 14 20:58:02 moonflo kernel: > [<ffffffff810888d1>] warn_slowpath_fmt+0x41/0x50 Oct 14 20:58:02 moonflo > kernel: [<ffffffff812b31c5>] ? add_interrupt_randomness+0x35/0x1e0 Oct 14 > 20:58:02 moonflo kernel: [<ffffffff8145b819>] dev_watchdog+0x259/0x270 Oct > 14 20:58:02 moonflo kernel: [<ffffffff8145b5c0>] ? > dev_graft_qdisc+0x80/0x80 Oct 14 20:58:02 moonflo kernel: > [<ffffffff8145b5c0>] ? dev_graft_qdisc+0x80/0x80 Oct 14 20:58:02 moonflo > kernel: [<ffffffff810d4047>] call_timer_fn.isra.30+0x17/0x70 Oct 14 > 20:58:02 moonflo kernel: [<ffffffff810d42a6>] > run_timer_softirq+0x176/0x2b0 Oct 14 20:58:02 moonflo kernel: > [<ffffffff8108bd0a>] __do_softirq+0xda/0x1f0 Oct 14 20:58:02 moonflo > kernel: [<ffffffff8108c04e>] irq_exit+0x7e/0xa0 Oct 14 20:58:02 moonflo > kernel: [<ffffffff8130e075>] xen_evtchn_do_upcall+0x35/0x50 Oct 14 > 20:58:02 moonflo kernel: [<ffffffff814e1e8e>] > xen_do_hypervisor_callback+0x1e/0x40 Oct 14 20:58:02 moonflo kernel: <EOI> > [<ffffffff810013aa>] ? xen_hypercall_sched_op+0xa/0x20 Oct 14 20:58:02 > moonflo kernel: [<ffffffff810013aa>] ? xen_hypercall_sched_op+0xa/0x20 Oct > 14 20:58:02 moonflo kernel: [<ffffffff810459e0>] ? xen_safe_halt+0x10/0x20 > Oct 14 20:58:02 moonflo kernel: [<ffffffff81053979>] ? > default_idle+0x9/0x10 Oct 14 20:58:02 moonflo kernel: [<ffffffff810542da>] > ? arch_cpu_idle+0xa/0x10 Oct 14 20:58:02 moonflo kernel: > [<ffffffff810bd170>] ? cpu_startup_entry+0x190/0x2f0 Oct 14 20:58:02 > moonflo kernel: [<ffffffff81047cd5>] ? cpu_bringup_and_idle+0x25/0x40 Oct > 14 20:58:02 moonflo kernel: ---[ end trace 98d961bae351244d ]--- Oct 14 > 20:58:02 moonflo kernel: r8169 0000:37:04.0 enp55s4: link up > > > After that, there are lots of messages about the link being up, one message > every 12 seconds. When you unplug the network cable, you get a message that > the link is down, and no message when you plug it in again. > > I was hoping that switching the network card (to one that uses a different > driver) might solve the problem, and it did not. Now I can only guess that > the network card goes to sleep and sometimes cannot be woken up again. > > I tried to reduce the connection speed to 100Mbit and found that accessing > the VMs (via RDP) becomes too slow to use them. So I disabled the power > management of the network card (through sysfs) and will have to see if the > problem persists. > > We'll be getting decent network cards in a couple days, but since the > problem doesn't seem to be related to a particular card/model/manufacturer, > that might not fix it, either. > > This problem seems to only occur on machines that operate as a xen server. > Other machines, identical Z800s, not running xen, run just fine. > > What would you suggest?
More info required: - Which version of Xen - Does this only occur with HVM guests? - Which network-driver are you using inside the guest - Can you connect to the "local" console of the guest? - If yes, does it still have no connectivity? I saw the same on my lab machine, which was related to: - Not using correct drivers inside HVM guests - Switch hardware not keeping the MAC/IP/Port lists long enough -- Joost
