The Environment
I have a small, dual-core Intel Atom-based server running CentOS 5.5 x64 with a slightly customized Xen kernel. It also has one on-board 10/100 NIC with an additional 3-port 10/100 NIC. Within this server, I also run a single Xen domU which functions as a firewall, DHCP server, and caching DNS forwarder. The domU is running CentOS 5.5 x64 as well, but with a stock Xen kernel.
I'm using the pciback kernel module to hide the 3-port NIC from the dom0 and assign it to my virtualized firewall. Eth1 is my public interface and the on-board NIC (eth0) is my private interface, which is on a XEN bridge and shared between both the Dom0 and DomU.
The Problem
The problem is that eth1 (the public interface on my virtualized firewall) decides to stop working several times a day. It seems to be related to usage: if I barely run much traffic across that interface, it might last a couple days. Heavy web browsing though will take it down in a couple hours. When it dies, this is the error in /var/log/messages on my firewall:
Jul 30 14:17:48 fw kernel: irq 18: nobody cared (try booting with the "irqpoll" option)
Jul 30 14:17:48 fw kernel:
Jul 30 14:17:48 fw kernel: Call Trace:
Jul 30 14:17:48 fw kernel: <IRQ> [<ffffffff802b3d60>] __report_bad_irq+0x30/0x7d
Jul 30 14:17:48 fw kernel: [<ffffffff802b3f97>] note_interrupt+0x1ea/0x22b
Jul 30 14:17:48 fw kernel: [<ffffffff802b348f>] __do_IRQ+0xbd/0x103
Jul 30 14:17:48 fw kernel: [<ffffffff80290319>] _local_bh_enable+0x61/0xc5
Jul 30 14:17:48 fw kernel: [<ffffffff8026df48>] do_IRQ+0xe7/0xf5
Jul 30 14:17:48 fw kernel: [<ffffffff803b3eca>] evtchn_do_upcall+0x13b/0x1fb
Jul 30 14:17:48 fw kernel: [<ffffffff802608d6>] do_hypervisor_callback+0x1e/0x2c
Jul 30 14:17:48 fw kernel: <EOI> [<ffffffff802063aa>] hypercall_page+0x3aa/0x1000
Jul 30 14:17:48 fw kernel: [<ffffffff802063aa>] hypercall_page+0x3aa/0x1000
Jul 30 14:17:48 fw kernel: [<ffffffff8026f4eb>] raw_safe_halt+0x84/0xa8
Jul 30 14:17:48 fw kernel: [<ffffffff8024ad2e>] cpu_idle+0x4a/0xba
Jul 30 14:17:48 fw kernel: [<ffffffff8026ca80>] xen_idle+0x38/0x4a
Jul 30 14:17:48 fw kernel: [<ffffffff8024ad7b>] cpu_idle+0x97/0xba
Jul 30 14:17:48 fw kernel: [<ffffffff8064cb0f>] start_kernel+0x21f/0x224
Jul 30 14:17:48 fw kernel: [<ffffffff8064c1e5>] _sinittext+0x1e5/0x1eb
Jul 30 14:17:48 fw kernel:
Jul 30 14:17:48 fw kernel: handlers:
Jul 30 14:17:48 fw kernel: [<ffffffff8811b8dd>] (rtl8139_interrupt+0x0/0x421 [8139too])
Jul 30 14:17:48 fw kernel: Disabling IRQ #18
Jul 30 14:18:02 fw kernel: NETDEV WATCHDOG: eth1: transmit timed out
Jul 30 14:18:05 fw kernel: eth1: link up, 100Mbps, full-duplex, lpa 0x41E1
Jul 30 14:18:17 fw kernel: NETDEV WATCHDOG: eth1: transmit timed out
Jul 30 14:18:20 fw kernel: eth1: link up, 100Mbps, full-duplex, lpa 0x41E1
Jul 30 14:18:32 fw kernel: NETDEV WATCHDOG: eth1: transmit timed out
I get a similar story in the Dom0's log. But as you can see, it completely disables the NIC's IRQ and shuts down the interface.
Jul 30 13:46:54 server kernel: irq 18: nobody cared (try booting with the "irqpoll" option)
Jul 30 13:46:54 server kernel:
Jul 30 13:46:54 server kernel: Call Trace:
Jul 30 13:46:54 server kernel: <IRQ> [<ffffffff802b3e13>] __report_bad_irq+0x30/0x7d
Jul 30 13:46:54 server kernel: [<ffffffff802b404a>] note_interrupt+0x1ea/0x22b
Jul 30 13:46:54 server kernel: [<ffffffff802b3542>] __do_IRQ+0xbd/0x103
Jul 30 13:46:54 server kernel: [<ffffffff8029044e>] _local_bh_enable+0x61/0xc5
Jul 30 13:46:54 server kernel: [<ffffffff8026df5a>] do_IRQ+0xe7/0xf5
Jul 30 13:46:54 server kernel: [<ffffffff803b3993>] evtchn_do_upcall+0x13b/0x1fb
Jul 30 13:46:54 server kernel: [<ffffffff802608d6>] do_hypervisor_callback+0x1e/0x2c
Jul 30 13:46:54 server kernel: <EOI> [<ffffffff802063aa>] hypercall_page+0x3aa/0x1000
Jul 30 13:46:54 server kernel: [<ffffffff802063aa>] hypercall_page+0x3aa/0x1000
Jul 30 13:46:54 server kernel: [<ffffffff8026f4fd>] raw_safe_halt+0x84/0xa8
Jul 30 13:46:54 server kernel: [<ffffffff8026ca92>] xen_idle+0x38/0x4a
Jul 30 13:46:54 server kernel: [<ffffffff8024b0b6>] cpu_idle+0x97/0xba
Jul 30 13:46:54 server kernel: [<ffffffff8064cb0f>] start_kernel+0x21f/0x224
Jul 30 13:46:54 server kernel: [<ffffffff8064c1e5>] _sinittext+0x1e5/0x1eb
Jul 30 13:46:54 server kernel:
Jul 30 13:46:54 server kernel: handlers:
Jul 30 13:46:54 server kernel: [<ffffffff803e7b6c>] (usb_hcd_irq+0x0/0x55)
Jul 30 13:46:54 server kernel: Disabling IRQ #18
Jul 30 14:26:06 server kernel: xenbr0: port 3(vif1.0) entering disabled state
Jul 30 14:26:06 server kernel: device vif1.0 left promiscuous mode
Jul 30 14:26:06 server kernel: xenbr0: port 3(vif1.0) entering disabled state
Jul 30 14:26:06 server kernel: ACPI: PCI interrupt for device 0000:02:04.0 disabled
Jul 30 14:26:06 server kernel: ACPI: PCI interrupt for device 0000:02:06.0 disabled
Jul 30 14:26:06 server kernel: ACPI: PCI interrupt for device 0000:02:07.0 disabled
The obvious answer is to do what the error message suggests and boot with the "irqpoll" option. However that has no affect, regardless of whether I boot the dom0 or the domU with "irqpoll". Does anyone have any suggestions? I'm getting somewhat desperate here…
Additional Technical Details
Truncated "lspci -vv" output on dom0:
02:04.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
Subsystem: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+
Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Interrupt: pin A routed to IRQ 18
Region 0: I/O ports at de00 [disabled] [size=256]
Region 1: Memory at fdeff000 (32-bit, non-prefetchable) [disabled] [size=256]
Capabilities: [50] Power Management version 2
Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0-,D1+,D2+,D3hot+,D3cold+)
Status: D0 PME-Enable- DSel=0 DScale=0 PME-
cat /proc/interrupts on dom0:
CPU0 CPU1 CPU2 CPU3
1: 8 0 0 0 Phys-irq i8042
4: 10 0 0 0 Phys-irq serial
8: 0 0 0 0 Phys-irq rtc
9: 0 0 0 0 Phys-irq acpi
12: 4 0 0 0 Phys-irq i8042
14: 162844 0 1910 0 Phys-irq ata_piix
15: 0 0 0 0 Phys-irq ata_piix
16: 0 0 0 0 Phys-irq uhci_hcd:usb5
17: 0 0 0 0 Phys-irq uhci_hcd:usb3
18: 200001 0 0 0 Phys-irq uhci_hcd:usb4
19: 2 0 0 0 Phys-irq ehci_hcd:usb1, uhci_hcd:usb2
254: 515869 0 0 33 Phys-irq peth0
256: 26214795 0 0 0 Dynamic-irq timer0
257: 26047 0 0 0 Dynamic-irq resched0
258: 54 0 0 0 Dynamic-irq callfunc0
259: 0 15252 0 0 Dynamic-irq resched1
260: 0 176 0 0 Dynamic-irq callfunc1
261: 0 768956 0 0 Dynamic-irq timer1
262: 0 0 96066 0 Dynamic-irq resched2
263: 0 0 175 0 Dynamic-irq callfunc2
264: 0 0 2193136 0 Dynamic-irq timer2
265: 0 0 0 30317 Dynamic-irq resched3
266: 0 0 0 132 Dynamic-irq callfunc3
267: 0 0 0 904610 Dynamic-irq timer3
268: 371 0 512 0 Dynamic-irq xenbus
NMI: 0 0 0 0
LOC: 0 0 0 0
ERR: 0
Truncated "/boot/grub/grub.conf" on dom0:
title CentOS (2.6.18-194.3.1.el5.sb_iq1xen)
root (hd0,0)
kernel /xen.gz-2.6.18-194.3.1.el5.sb_iq1
module /vmlinuz-2.6.18-194.3.1.el5.sb_iq1xen ro root=/dev/VolGroup00/LogVol00 xencons=off console=ttyS0,38400 irqpoll
module /initrd-2.6.18-194.3.1.el5.sb_iq1xen.img
Best Answer
If it is a capacity issue haven't you thought about simply setting up a traffic shaping rule so that you're less likely to exceed the benchmark?
http://torrent-invites.com/seedbox-tutorials/80552-howto-implementing-bandwidth-quota-traffic-shaping-your-dedicated-seedbox.html