thor's questions

I have a service (small http service that listens on 0.0.0.0:8080) written in python that starts at system boot. The problem is that sometimes at server boot it starts too soon, when even IPv4 is not yet initialized (?) by kernel. Serivce failes with error (from /var/log/upstart):

socket.gaierror: [Errno -9] Address family for hostname not supported

When starting manually later it starts normally. Adding 'sleep 30' in pre-start section also helps. But I would like to know if there is a better and cleaner way to specify in upstart configuration that this service needs working ipv4. It does not need full "routing" or default gateway or even configured loopback. All it needs is the ability to bind to "any" (0.0.0.0) IPv4 address.

We have a Fujitsu Primergy RX100 S7 server. It has two Gigabit Ethernet ports: Intel 82574L Gigabit Ethernet, Intel 82579LM Gigabit Ethernet. Cards use e1000e driver. I have installed Ubuntu 12.04 on the server. Both network cards fail to connect to (different) ethernet switches reporting there is no carrier.

Is there a known issue? Any workaround?

Updated:

lspci output:

00:00.0 Host bridge: Intel Corporation Xeon E3-1200 Processor Family DRAM Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:16.1 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #2 (rev 04)
00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b4)
00:1c.6 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 7 (rev b4)
00:1c.7 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 8 (rev b4)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a4)
00:1f.0 ISA bridge: Intel Corporation C202 Chipset Family LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family SATA AHCI Controller (rev 04)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04)
02:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 05)

Also, don't know why, second ethernet port (eth1) is detecting link. So only one of those ports can't see carrier. lshw:

second                
    description: Rack Mount Chassis
    product: PRIMERGY RX100 S7 (ABN:K1385-V201-24)
    vendor: FUJITSU
    version: GS05
    serial: YLAP014393
    width: 64 bits
    capabilities: smbios-2.7 dmi-2.7 vsyscall32
    configuration: boot=normal chassis=rackmount family=SERVER sku=ABN:K1385-V201-24 uuid=C0CD0617-7F24-11E1-A334-2B3D2BBF72F6
  *-core
       description: Motherboard
       product: D3034-A1
       vendor: FUJITSU
       physical id: 0
       version: S26361-D3034-A100 WGS01 GS03
       serial: LJ3A-P01950
     *-firmware
          description: BIOS
          vendor: FUJITSU // American Megatrends Inc.
          physical id: 0
          version: V4.6.4.1 R1.21.0 for D3034-A1x
          date: 03/16/2012
          size: 64KiB
          capacity: 8128KiB
          capabilities: pci upgrade shadowing cdboot bootselect edd int5printscreen int9keyboard int14serial int17printer acpi usb biosbootspecification
     *-cache:0
          description: L1 cache
          physical id: 4
          size: 256KiB
          capacity: 256KiB
          capabilities: internal varies
     *-cache:1
          description: L2 cache
          physical id: 5
          size: 1MiB
          capacity: 1MiB
          capabilities: internal varies unified
     *-cache:2
          description: L3 cache
          physical id: 6
          size: 8MiB
          capacity: 8MiB
          capabilities: internal varies unified
     *-memory
          description: System Memory
          physical id: 24
          slot: System board or motherboard
          size: 8GiB
        *-bank:0
             description: DIMM Synchronous [empty]
             product: Array1_PartNumber0
             vendor: A1_Manufacturer0
             physical id: 0
             serial: A1_SerNum0
             slot: DIMM-2A
             width: 64 bits
        *-bank:1
             description: DIMM DDR3 Synchronous 1333 MHz (0.8 ns)
             product: M391B5273DH0-YK0
             vendor: Samsung
             physical id: 1
             serial: 3357D4F4
             slot: DIMM-1A
             size: 4GiB
             width: 64 bits
             clock: 1333MHz (0.8ns)
        *-bank:2
             description: DIMM Synchronous [empty]
             product: Array1_PartNumber2
             vendor: A1_Manufacturer2
             physical id: 2
             serial: A1_SerNum2
             slot: DIMM-2B
             width: 64 bits
        *-bank:3
             description: DIMM DDR3 Synchronous 1333 MHz (0.8 ns)
             product: M391B5273DH0-YK0
             vendor: Samsung
             physical id: 3
             serial: 3357D24B
             slot: DIMM-1B
             size: 4GiB
             width: 64 bits
             clock: 1333MHz (0.8ns)
     *-cpu
          description: CPU
          product: Intel(R) Xeon(R) CPU E31220 @ 3.10GHz
          vendor: Intel Corp.
          physical id: 3e
          bus info: cpu@0
          version: Intel(R) Xeon(R) CPU E31220 @ 3.10GHz
          slot: SOCKET 0
          size: 1600MHz
          capacity: 3800MHz
          width: 64 bits
          clock: 100MHz
          capabilities: x86-64 fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts tpr_shadow vnmi flexpriority ept vpid cpufreq
          configuration: cores=4 enabledcores=4 threads=4
     *-pci
          description: Host bridge
          product: Xeon E3-1200 Processor Family DRAM Controller
          vendor: Intel Corporation
          physical id: 100
          bus info: pci@0000:00:00.0
          version: 09
          width: 32 bits
          clock: 33MHz
        *-communication:0
             description: Communication controller
             product: 6 Series/C200 Series Chipset Family MEI Controller #1
             vendor: Intel Corporation
             physical id: 16
             bus info: pci@0000:00:16.0
             version: 04
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: driver=mei latency=0
             resources: irq:49 memory:fba26000-fba2600f
        *-communication:1 UNCLAIMED
             description: Communication controller
             product: 6 Series/C200 Series Chipset Family MEI Controller #2
             vendor: Intel Corporation
             physical id: 16.1
             bus info: pci@0000:00:16.1
             version: 04
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list
             configuration: latency=0
             resources: memory:fba25000-fba2500f
        *-network
             description: Ethernet interface
             product: 82579LM Gigabit Network Connection
             vendor: Intel Corporation
             physical id: 19
             bus info: pci@0000:00:19.0
             logical name: eth0
             version: 04
             serial: 00:22:4d:67:d3:52
             capacity: 1Gbit/s
             width: 32 bits
             clock: 33MHz
             capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
             configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=1.5.1-k firmware=0.13-4 ip=195.158.12.79 latency=0 link=no multicast=yes port=twisted pair
             resources: irq:45 memory:fba00000-fba1ffff memory:fba24000-fba24fff ioport:f040(size=32)
        *-usb:0
             description: USB controller
             product: 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2
             vendor: Intel Corporation
             physical id: 1a
             bus info: pci@0000:00:1a.0
             version: 04
             width: 32 bits
             clock: 33MHz
             capabilities: pm debug ehci bus_master cap_list
             configuration: driver=ehci_hcd latency=0
             resources: irq:16 memory:fba23000-fba233ff
        *-pci:0
             description: PCI bridge
             product: 6 Series/C200 Series Chipset Family PCI Express Root Port 1
             vendor: Intel Corporation
             physical id: 1c
             bus info: pci@0000:00:1c.0
             version: b4
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:41
        *-pci:1
             description: PCI bridge
             product: 6 Series/C200 Series Chipset Family PCI Express Root Port 7
             vendor: Intel Corporation
             physical id: 1c.6
             bus info: pci@0000:00:1c.6
             version: b4
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:42 ioport:e000(size=4096) memory:fb900000-fb9fffff
           *-network
                description: Ethernet interface
                product: 82574L Gigabit Network Connection
                vendor: Intel Corporation
                physical id: 0
                bus info: pci@0000:02:00.0
                logical name: eth1
                version: 00
                serial: 00:22:4d:67:d3:51
                size: 100Mbit/s
                capacity: 1Gbit/s
                width: 32 bits
                clock: 33MHz
                capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
                configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=1.5.1-k duplex=full firmware=2.1-0 ip=192.168.5.236 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
                resources: irq:18 memory:fb900000-fb91ffff ioport:e000(size=32) memory:fb920000-fb923fff
        *-pci:2
             description: PCI bridge
             product: 6 Series/C200 Series Chipset Family PCI Express Root Port 8
             vendor: Intel Corporation
             physical id: 1c.7
             bus info: pci@0000:00:1c.7
             version: b4
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:43 memory:fa000000-fb8fffff
           *-display UNCLAIMED
                description: VGA compatible controller
                product: MGA G200e [Pilot] ServerEngines (SEP1)
                vendor: Matrox Graphics, Inc.
                physical id: 0
                bus info: pci@0000:03:00.0
                version: 05
                width: 32 bits
                clock: 33MHz
                capabilities: pm pciexpress msi vga_controller bus_master cap_list
                configuration: latency=0
                resources: memory:fa000000-faffffff memory:fb800000-fb803fff memory:fb000000-fb7fffff
        *-usb:1
             description: USB controller
             product: 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1
             vendor: Intel Corporation
             physical id: 1d
             bus info: pci@0000:00:1d.0
             version: 04
             width: 32 bits
             clock: 33MHz
             capabilities: pm debug ehci bus_master cap_list
             configuration: driver=ehci_hcd latency=0
             resources: irq:23 memory:fba22000-fba223ff
        *-pci:3
             description: PCI bridge
             product: 82801 PCI Bridge
             vendor: Intel Corporation
             physical id: 1e
             bus info: pci@0000:00:1e.0
             version: a4
             width: 32 bits
             clock: 33MHz
             capabilities: pci subtractive_decode bus_master cap_list
        *-isa
             description: ISA bridge
             product: C202 Chipset Family LPC Controller
             vendor: Intel Corporation
             physical id: 1f
             bus info: pci@0000:00:1f.0
             version: 04
             width: 32 bits
             clock: 33MHz
             capabilities: isa bus_master cap_list
             configuration: latency=0
        *-storage
             description: SATA controller
             product: 6 Series/C200 Series Chipset Family SATA AHCI Controller
             vendor: Intel Corporation
             physical id: 1f.2
             bus info: pci@0000:00:1f.2
             logical name: scsi0
             logical name: scsi1
             logical name: scsi4
             version: 04
             width: 32 bits
             clock: 66MHz
             capabilities: storage msi pm ahci_1.0 bus_master cap_list emulated
             configuration: driver=ahci latency=0
             resources: irq:44 ioport:f090(size=8) ioport:f080(size=4) ioport:f070(size=8) ioport:f060(size=4) ioport:f020(size=32) memory:fba21000-fba217ff
           *-disk:0
                description: ATA Disk
                product: WDC WD5003ABYX-5
                vendor: Western Digital
                physical id: 0
                bus info: scsi@0:0.0.0
                logical name: /dev/sda
                version: 01.0
                serial: WD-WMAYP3337465
                size: 465GiB (500GB)
                capabilities: partitioned partitioned:dos
                configuration: ansiversion=5 signature=00000e30
              *-volume
                   description: Linux raid autodetect partition
                   physical id: 1
                   bus info: scsi@0:0.0.0,1
                   logical name: /dev/sda1
                   capacity: 465GiB
                   capabilities: primary multi
           *-disk:1
                description: ATA Disk
                product: WDC WD5003ABYX-5
                vendor: Western Digital
                physical id: 1
                bus info: scsi@1:0.0.0
                logical name: /dev/sdb
                version: 01.0
                serial: WD-WMAYP3301496
                size: 465GiB (500GB)
                capabilities: partitioned partitioned:dos
                configuration: ansiversion=5 signature=00051613
              *-volume
                   description: Linux raid autodetect partition
                   physical id: 1
                   bus info: scsi@1:0.0.0,1
                   logical name: /dev/sdb1
                   capacity: 465GiB
                   capabilities: primary bootable multi
           *-cdrom
                description: DVD-RAM writer
                product: DVD RW AD-7760H
                vendor: Optiarc
                physical id: 0.0.0
                bus info: scsi@4:0.0.0
                logical name: /dev/cdrom
                logical name: /dev/cdrw
                logical name: /dev/dvd
                logical name: /dev/dvdrw
                logical name: /dev/sr0
                version: 1.41
                capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
                configuration: ansiversion=5 status=nodisc
        *-serial UNCLAIMED
             description: SMBus
             product: 6 Series/C200 Series Chipset Family SMBus Controller
             vendor: Intel Corporation
             physical id: 1f.3
             bus info: pci@0000:00:1f.3
             version: 04
             width: 64 bits
             clock: 33MHz
             configuration: latency=0
             resources: memory:fba20000-fba200ff ioport:f000(size=32)

dmesg|egrep -e 'eth|e1000'

[    0.563797] i2c-core: driver [aat2870] using legacy suspend method
[    0.563799] i2c-core: driver [aat2870] using legacy resume method
[    1.364353] e1000e: Intel(R) PRO/1000 Network Driver - 1.5.1-k
[    1.364358] e1000e: Copyright(c) 1999 - 2011 Intel Corporation.
[    1.364388] e1000e 0000:00:19.0: PCI INT A -> GSI 20 (level, low) -> IRQ 20
[    1.364398] e1000e 0000:00:19.0: setting latency timer to 64
[    1.364486] e1000e 0000:00:19.0: irq 45 for MSI/MSI-X
[    1.669276] e1000e 0000:00:19.0: eth0: (PCI Express:2.5GT/s:Width x1) 00:22:4d:67:d3:52
[    1.669281] e1000e 0000:00:19.0: eth0: Intel(R) PRO/1000 Network Connection
[    1.669332] e1000e 0000:00:19.0: eth0: MAC: 10, PHY: 11, PBA No: 313130-031
[    1.669342] e1000e 0000:02:00.0: Disabling ASPM L0s 
[    1.669356] e1000e 0000:02:00.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18
[    1.669379] e1000e 0000:02:00.0: setting latency timer to 64
[    1.669612] e1000e 0000:02:00.0: irq 46 for MSI/MSI-X
[    1.669616] e1000e 0000:02:00.0: irq 47 for MSI/MSI-X
[    1.669619] e1000e 0000:02:00.0: irq 48 for MSI/MSI-X
[    1.775587] e1000e 0000:02:00.0: eth1: (PCI Express:2.5GT/s:Width x1) 00:22:4d:67:d3:51
[    1.775592] e1000e 0000:02:00.0: eth1: Intel(R) PRO/1000 Network Connection
[    1.775678] e1000e 0000:02:00.0: eth1: MAC: 3, PHY: 8, PBA No: 313130-033
[    4.856622] ADDRCONF(NETDEV_UP): eth0: link is not ready
[    4.856627] ADDRCONF(NETDEV_UP): eth1: link is not ready
[    5.244134] ADDRCONF(NETDEV_UP): eth1: link is not ready
[    5.387671] e1000e 0000:00:19.0: irq 45 for MSI/MSI-X
[    5.443255] e1000e 0000:00:19.0: irq 45 for MSI/MSI-X
[    5.443706] ADDRCONF(NETDEV_UP): eth0: link is not ready
[    6.871987] e1000e: eth1 NIC Link is Up 100 Mbps Full Duplex, Flow Control: None
[    6.871991] e1000e 0000:02:00.0: eth1: 10/100 speed: disabling TSO
[    6.872558] ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[   17.480573] eth1: no IPv6 routers present
[  148.624087] e1000e: eth1 NIC Link is Down
[  226.515981] e1000e: eth1 NIC Link is Up 100 Mbps Full Duplex, Flow Control: None
[  226.515987] e1000e 0000:02:00.0: eth1: 10/100 speed: disabling TSO

We have a virtual server named Jira running under VirtualBox 4.0 (host is Debian Squeeze). At some point in time a VM failed to boot, so we had to boot from GRML rescue iso. Before doing that we have created a snapshot of VM. After fixing boot problems VM continued to use that snapshot as it's current state. This is the output of VBoxManage showvminfo jira:

Name:            jira
Guest OS:        Other/Unknown
UUID:            ef5260be-46d3-45cb-8c9d-9f9e322f9110
Config file:     /home/vbox/.VirtualBox/Machines/jira/jira.xml
Snapshot folder: /home/vbox/.VirtualBox/Machines/jira/Snapshots
Log folder:      /home/vbox/.VirtualBox/Machines/jira/Logs
Hardware UUID:   ef5260be-46d3-45cb-8c9d-9f9e322f9110
Memory size:     2048MB
Page Fusion:     off
VRAM size:       8MB
HPET:            off
Chipset:         piix3
Firmware:        BIOS
Number of CPUs:  1
Synthetic Cpu:   off
CPUID overrides: None
Boot menu mode:  message and menu
Boot Device (1): Floppy
Boot Device (2): DVD
Boot Device (3): HardDisk
Boot Device (4): Not Assigned
ACPI:            on
IOAPIC:          on
PAE:             on
Time offset:     0 ms
RTC:             local time
Hardw. virt.ext: on
Hardw. virt.ext exclusive: on
Nested Paging:   on
Large Pages:     off
VT-x VPID:       on
State:           running (since 2012-05-24T12:23:48.127000000)
Monitor count:   1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address: 
Teleporter Password: 
Storage Controller Name (0):            jira.sata
Storage Controller Type (0):            IntelAhci
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0):  30
Storage Controller Port Count (0):      30
Storage Controller Bootable (0):        on
Storage Controller Name (1):            jira.ata
Storage Controller Type (1):            PIIX4
Storage Controller Instance Number (1): 0
Storage Controller Max Port Count (1):  2
Storage Controller Port Count (1):      2
Storage Controller Bootable (1):        on
jira.sata (0, 0): /home/vbox/.VirtualBox/Machines/jira/Snapshots/{e8bedcaa-278b-4b06-a825-1dddc9e4fdb3}.vdi (UUID: e8bedcaa-278b-4b06-a825-1dddc9e4fdb3)
NIC 1:           MAC: 080027ABB6DD, Attachment: Bridged Interface 'eth0.100', Cable connected: on, Trace: off (file: none), Type: Am79C973, Reported speed: 0 Mbps, Boot priority: 0
NIC 2:           disabled
NIC 3:           disabled
NIC 4:           disabled
NIC 5:           disabled
NIC 6:           disabled
NIC 7:           disabled
NIC 8:           disabled
Pointing Device: PS/2 Mouse
Keyboard Device: PS/2 Keyboard
UART 1:          disabled
UART 2:          disabled
Audio:           disabled
Clipboard Mode:  Bidirectional
Video mode:      720x400x0
VRDE:            enabled (Address 0.0.0.0, Ports 3389, MultiConn: off, ReuseSingleConn: off, Authentication type: null)
Video redirection: disabled
USB:             disabled

USB Device Filters:

<none>

Available remote USB devices:

<none>

Currently Attached USB Devices:

<none>

Shared folders:  <none>

VRDE Connection:    not active
Clients so far:     0

Guest:

OS type:                             Other
Additions run level:                 0
Configured memory balloon size:      0 MB

Snapshots:

   Name: beforeGRML (UUID: 70949bb5-985a-4ae6-ba28-3d0475434cf0) *

As you can see, snapshot is named beforeGRML. Actually I suspect that this snapshot is current state, and disk image is a state before we have recovered the machine with GRML iso.

My questions:

• is it correct that beforeGRML snapshot is actually a current state?
• whatever a 'current state' is, I want to merge it with VM disk and have no snapshots - how to do that?

Please note that VM is hosted at a remote Debian server and I use VBoxManage command line interface. (I've tried reading documentation but still can't figure out what all those 'snapshot delete' and 'snapshot restore' would do.)

We have a local network that is connected to internet through linux gateway. There are about 50 workstations in LAN. We recently started observing a problem that gateway sporadically stops responding for several seconds. After investigation, we have noticed that sometimes, when gateway is not able to ping some workstation, it does not even try to send ARP requests to it.

As an example, we ping 192.168.5.37 from gateway:

PING 192.168.5.37 (192.168.5.37) 56(84) bytes of data.
From 192.168.5.1 icmp_seq=1 Destination Host Unreachable
From 192.168.5.1 icmp_seq=2 Destination Host Unreachable
From 192.168.5.1 icmp_seq=3 Destination Host Unreachable
From 192.168.5.1 icmp_seq=5 Destination Host Unreachable
From 192.168.5.1 icmp_seq=6 Destination Host Unreachable
From 192.168.5.1 icmp_seq=7 Destination Host Unreachable
64 bytes from 192.168.5.37: icmp_seq=8 ttl=128 time=438 ms
64 bytes from 192.168.5.37: icmp_seq=9 ttl=128 time=0.240 ms
64 bytes from 192.168.5.37: icmp_seq=10 ttl=128 time=0.238 ms

At the same time, tcpdump is running on the other console:

sudo tcpdump -nli eth0 host 192.168.5.37
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
14:12:26.944842 IP 192.168.5.37.6112 > 255.255.255.255.6112: UDP, length 16
14:12:31.951145 IP 192.168.5.37.6112 > 255.255.255.255.6112: UDP, length 16
14:12:36.958632 IP 192.168.5.37.6112 > 255.255.255.255.6112: UDP, length 16
14:12:39.914620 arp who-has 192.168.5.37 tell 192.168.5.1
14:12:39.914775 arp reply 192.168.5.37 is-at 00:0b:6a:86:53:14
14:12:39.914781 IP 192.168.5.1 > 192.168.5.37: ICMP echo request, id 50734, seq 8, length 64
14:12:39.914955 IP 192.168.5.37 > 192.168.5.1: ICMP echo reply, id 50734, seq 8, length 64
14:12:40.480035 IP 192.168.5.1 > 192.168.5.37: ICMP echo request, id 50734, seq 9, length 64
14:12:40.480264 IP 192.168.5.37 > 192.168.5.1: ICMP echo reply, id 50734, seq 9, length 64
14:12:41.480037 IP 192.168.5.1 > 192.168.5.37: ICMP echo request, id 50734, seq 10, length 64
14:12:41.480265 IP 192.168.5.37 > 192.168.5.1: ICMP echo reply, id 50734, seq 10, length 64

I would suspect that something is wrong with kernel ARP cache. By default, gc_thresh1 is at 512, and we have ten times less hosts in a lan (ip nei|wc -l is about 50)..

What is the problem and how can we fix it?

I have three processes running on Intel Core 2 Duo CPU. From watching output of 'top' and graphs of CPU load (drawn by MRTG, data collection via SNMP) I can see that CPU load is never more than 50%, and, most of the day, when those processes are busy CPU load has a ceiling at 50 %. I mean, CPU load grows up to 50% in the morning and stays there until late evening.

My first thought was that only one core was used at 100% thus giving 50% of both CPUs. But, as there are three processes running and from 'top' I see that both cores are being loaded, so this is not the case. schedtool shows that CPU affinity for those three processes is at default, 0x03, allowing them to use both cores. If I force one process to one core (schedtool -a 0x01), and two others to second (schedtool -a 0x02), cumulative usage grows beyond 50%.

Why three processes seem to consume only 50% of two cores? Why forcing them to different CPUs allows usage to grow higher? Any hints?

P.S. Processes in question are Counter-Strike servers.

I have a Debian Lenny web server. It is running apache2 with libapache2-mod-suphp. Unfortunately, suphp makes impossible to use phpmyadmin, as phpmyadmin is installed in /usr/share/phpmyadmin and owned by root, and suphp disables it's engine in this direcory:

$ cat /etc/apache2/mods-enabled/suphp.conf 
<IfModule mod_suphp.c>
    AddType application/x-httpd-php .php .php3 .php4 .php5 .phtml
    suPHP_AddHandler application/x-httpd-php
    <Directory />
        suPHP_Engine on
    </Directory>

    # By default, disable suPHP for debian packaged web applications as files
    # are owned by root and cannot be executed by suPHP because of min_uid.
    <Directory /usr/share>
        suPHP_Engine off
    </Directory>
</IfModule>

Is there a possibility to enable system phpmyadmin (may be through standard libapache2-mod-php5) while using suphp? How?

I have a linux machine (my workstation). From there I can ping other local machines, let's say 192.168.1.22. Let's say I want to prohibit communication with 192.168.1.22 by it's MAC address. I'm trying a simple rule:

ebtables -I INPUT -s 00:24:1d:c9:0a:27 -j DROP

But still I can ping that host. Is ebtables limited to filtering traffic only on bridge interfaces?

I know a tool arping, which I used successfully in the past. But today when I tried it, it failed to ping a host which is alive.

My IP address in local network is 192.168.1.20. Other computer's address is 192.168.1.63. If I do:

arping -I eth0 192.168.1.63

I see no responses. If I just ping 192.168.63, it works, and ARP resolution works too, of course. Tcpdump shows that arping sends it's ARP requests (who has 192.168.1.63) to MAC address ff:1a:ff:24:00:b8 instead of broadcast. When I do ping, ARP requests goes to normal broadcast ff:ff:ff:ff:ff:ff, and there is a reply.

What's wrong with my arping?

P.S. System is Ubuntu 10.10.

Currently, we have a single server hosting all content: music, video and software. This content is downloaded by users through HTTP. Now free space is coming to an end and we are exploring different ways of extending our storage capacity. We want to do it cheap, simple and reliable (protected from disk/ server faults). Currenly, we see two ways:

1. Add a couple of cheap servers with 4 disks (RAID1 ?), run some distributed file-system on top, like GlusterFS. Pros: hopefully, we will see all our disks as single flat file system, just dump content into it and be done. Cons: could be tricky in configuration and handling of faults.

2. Add a couple of cheap servers, all running HTTP servers. Each piece of content (be it a music file or video) is placed on randomly selected two servers. Pros: don't have to deal with RAID, as content is duplicated; single server failure does not bring down any part of content; doubled distribution capacity (as any signle file could be downloaded from any of two servers hosting it). Cons: requires some scripting on part of distribution of content, adding/ removing servers.

Do we miss any other ways? Which of the aforementioned options seems to be the best?