Switched On Tech Design

Tag: setup

  • How to install the NFS client packages on Fedora 20 and automatically mount NFS shares

     

    We were asked how to set up a Fedora 20 virtual machine to access folders on an already-set-up Ubuntu Server machine using NFS. A folder has been created on the Fedora VM to mount the NFS share to (/opt/documents in this case). First we install the relevant packages on Fedora:

     

    sudo yum install nfs-utils nfs-utils-lib

     

    Examine the package list, and if nothing looks awry hit Y to install. Now edit your fstab and add this line to the bottom to automount the shares:

     

    [ip.of.nfs.server]:[absolute-path-to-share] [absolute-path-to-fedora-mount-point] nfs auto 0 0

     

    e.g., in this example:

     

    10.1.1.3:/tank/documents /opt/documents nfs auto 0 0

     

    To break this down: the static IP address of the NFS server is 10.1.1.3, the path on the Ubuntu machine to the share is /tank/documents, and the created directory to mount the NFS share to is /opt/documents on the Fedora VM. To mount everything in fstab, run:

     

    mount -a

     

    Then navigate to the /opt/documents directory and check that you can read/write onto the NFS share correctly. Reboot the server to make sure everything works OK and you should be done!

  • XenServer 6.2: How to set up passthrough of a PCI or PCI-Express device

     

    This is done by logging in as the root user to your XenServer system via SSH. To see the PCI devices available to your system, enter the following command:

     

    lspci

     

    Here is an example result:

     

    00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 Northbridge only dual slot (2×16) PCI-e GFX Hydra part (rev 02)
    00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD/ATI] RD990 I/O Memory Management Unit (IOMMU)
    00:02.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (PCI express gpp port B)
    00:09.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (PCI express gpp port H)
    00:0a.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (external gfx1 port A)
    00:0b.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890 PCI to PCI bridge (NB-SB link)
    00:0c.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] RD890S PCI Express bridge for GPP2 port 1
    00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
    00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
    00:12.1 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller
    00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
    00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
    00:13.1 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller
    00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
    00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller (rev 3d)
    00:14.1 IDE interface: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 IDE Controller
    00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller
    00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge
    00:14.5 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI2 Controller
    00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 0
    00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 1
    00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 2
    00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 3
    00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 4
    00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 5
    00:19.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 0
    00:19.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 1
    00:19.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 2
    00:19.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 3
    00:19.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 4
    00:19.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 5
    00:1a.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 0
    00:1a.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 1
    00:1a.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 2
    00:1a.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 3
    00:1a.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 4
    00:1a.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 5
    00:1b.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 0
    00:1b.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 1
    00:1b.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 2
    00:1b.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 3
    00:1b.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 4
    00:1b.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h Processor Function 5
    01:01.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics Family (rev 10)
    01:03.0 Multimedia audio controller: C-Media Electronics Inc CMI8788 [Oxygen HD Audio]
    02:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
    03:00.0 Multimedia controller: Philips Semiconductors SAA7164 (rev 81)
    04:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
    05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
    06:00.0 InfiniBand: Mellanox Technologies MT26418 [ConnectX VPI PCIe 2.0 5GT/s – IB DDR / 10GigE] (rev b0)

    As you might guess from some of the lines, it’s an AMD server. You’ll notice some USB controllers, likely a SATA controller and any PCI or PCI Express add-in cards (usually at the bottom). In this example we will pass through a digital TV card to a VM so we can record free-to-air TV. The controller here is the fourth-last entry:

     

    03:00.0 Multimedia controller: Philips Semiconductors SAA7164 (rev 81)

     

    It’s a Digital Now PCI-E card – as you can see there’s no mention of the brand in the chipset that the system can see, so you may have to make an educated guess (or do some research as to what’s actually used in the card) to determine which one you want. Making note of the above line, we now edit /boot/extlinux.conf:

     

    vi /boot/extlinux.conf

     

    In our example system it looks like this:

     

    # location mbr
    serial 0 115200
    default xe
    prompt 1
    timeout 50

    label xe
    # XenServer
    kernel mboot.c32
    append /boot/xen.gz mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 console=vga vga=mode-0x0311 — /boot/vmlinuz-2.6-xen root=LABEL=root-ckwntldj ro xencons=hvc console=hvc0 console=tty0 quiet vga=785 splashi  — /boot/initrd-2.6-xen.img

    label xe-serial
    # XenServer (Serial)
    kernel mboot.c32
    append /boot/xen.gz com1=115200,8n1 console=com1,vga mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 — /boot/vmlinuz-2.6-xen root=LABEL=root-ckwntldj ro console=tty0 xencons=hvc console=hvc0 — /boot/initrd-2.6-xen.img

    label safe
    # XenServer in Safe Mode
    kernel mboot.c32
    append /boot/xen.gz nosmp noreboot noirqbalance acpi=off noapic mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M com1=115200,8n1 console=com1,vga — /boot/vmlinuz-2.6-xen nousb root=LABEL=root-ckwntldj ro console=tty0 xencons=hvc console=hvc0 — /boot/initrd-2.6-xen.img

    label fallback
    # XenServer (Xen 4.1.5 / Linux 2.6.32.43-0.4.1.xs1.8.0.835.170778xen)
    kernel mboot.c32
    append /boot/xen-4.1.5.gz mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 — /boot/vmlinuz-2.6.32.43-0.4.1.xs1.8.0.835.170778xen root=LABEL=root-ckwntldj ro xencons=hvc console=hvc0 console=tty0 — /boot/initrd-2.6.32.43-0.4.1.xs1.8.0.835.170778xen.img

    label fallback-serial
    # XenServer (Serial, Xen 4.1.5 / Linux 2.6.32.43-0.4.1.xs1.8.0.835.170778xen)
    kernel mboot.c32
    append /boot/xen-4.1.5.gz com1=115200,8n1 console=com1,vga mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 — /boot/vmlinuz-2.6.32.43-0.4.1.xs1.8.0.835.170778xen root=LABEL=root-ckwntldj ro console=tty0 xencons=hvc console=hvc0 — /boot/initrd-2.6.32.43-0.4.1.xs1.8.0.835.170778xen.img

    Rather an intimidating-looking file if you’re new to *nix config files. Fortunately, we can ignore most of this and just pay attention to the last line in the “label xe” section at the top. The line we want to edit is:

     

    append /boot/xen.gz mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 console=vga vga=mode-0x0311 — /boot/vmlinuz-2.6-xen root=LABEL=root-ckwntldj ro xencons=hvc console=hvc0 console=tty0 quiet vga=785 splashi  — /boot/initrd-2.6-xen.img

     

    Looking at the line we wanted from lspci above, we want the number at the front – in this case:

     

    03:00.0

     

    Add the following near the end of the config line – inbetween “splashi” and “—“:

     

    pciback.hide=(03:00.0)

     

    The line should now read:

     

      append /boot/xen.gz mem=1024G dom0_max_vcpus=4 dom0_mem=4096M,max:4096M watchdog_timeout=300 lowmem_emergency_pool=1M crashkernel=64M@32M cpuid_mask_xsave_eax=0 console=vga vga=mode-0x0311 — /boot/vmlinuz-2.6-xen root=LABEL=root-ckwntldj ro xencons=hvc console=hvc0 console=tty0 quiet vga=785 splashi pciback.hide=(03:00.0) — /boot/initrd-2.6-xen.img

    Note the space on either side – one between splashi and the new text and one between the hyphens and the new text. Now run:

     

    extlinux -i /boot

     

    Then shut down any VMs and reboot the server:

     

    reboot

     

    Once it is back up, we need to find the UUID of the virtual machine we want to pass the device through to. Run:

     

    xe vm-list

     

    This will return a result for every VM on the system – it might be quite long! If it is a long list you may wish to pipe it to the less command for easier viewing:

     

    xe vm-list | less

     

    If you aren’t familiar with less you can exit with the “q” key. Sort through the list until you find the VM you want to pass through to. In this example it is:

     

    uuid ( RO)           : 6b664553-6822-b445-5a8c-c10d93c41c4c
    name-label ( RW): bacchus
    power-state ( RO): halted

    Now we can add the PCI device to the config of this VM:

     

    xe vm-param-set other-config:pci=0/0000:03:00.0 uuid=6b664553-6822-b445-5a8c-c10d93c41c4c

     

    Breaking that down:

     

    xe vm-param-set other-config:pci=0/0000:[PCI address for the device] uuid=[UUID of VM]

     

    Starting the VM – in this case a Windows 7 VM – we can check for the device to see that it has appeared (in this case the drivers were already installed so it has been immediately identified):

     

    xenserver-passthrough-to-windows

    Success! In a Linux system you should be able to do:

     

    lspci

     

    to see the newly passed through hardware.

  • How to set up SNMP monitoring (snmpd) on Ubuntu 12.04

     

    This one caused a bit of hassle recently – a few online guides don’t seem to work with the current version of Ubuntu. We found that this works, at least in the ~10 or so servers we have tried so far:

     

    sudo apt-get install snmpd

     

    Back up your snmpd.conf file:

     

    sudo mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.old

     

    Create a new file:

     

    sudo touch /etc/snmp/snmpd.conf

     

    Edit with your chosen editor and put in the following:

     

    rocommunity public

    syslocation “Describe the server’s location”

    syscontact [email protected]

     

    Save and exit. Now edit the following file:

     

    /etc/default/snmpd

     

    Comment out the following line by putting a # before it:

     

    SNMPDOPTS=’-Lsd -Lf /dev/null -u snmp -g snmp -I -smux -p /var/run/snmpd.pid’

     

    On the next blank line add the following:

     

    SNMPDOPTS=’-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid -c /etc/snmp/snmpd.conf’

     

    Save the file and restart the SNMP daemon:

     

    sudo /etc/init.d/snmpd restart

     

    Now you should be able to successfully snmpwalk locally and from machines on the local network.

  • MythTV backend DVB adapter error: ERROR_OPEN

     

    If you see the above error when you’re trying to set up your DVB tuner card one cause is that MythTV can’t get access to the tuner card. This can be because there’s another application installed which has access to it, e.g. something like TVHeadend. On XBMCBuntu you can uninstall TVHeadend by running the following:

     

    apt-get remove tvheadend

    apt-get purge tvheadend

     

    …then retry the setup. If that was the problem it should pick the tuner up now without issue, showing the tuner name in place of ERROR_OPEN.