Switched On Tech Design

Tag: multiple

  • XenServer 6.2: Passing through multiple PCI or PCI Express devices to a Virtual Machine (VM)

     

    Following the previous article on passing through a PCI or PCI Express card to a virtual machine someone asked what the syntax was to pass through multiple devices to a VM. Using our previous system as an example, we run lspci to find each item we want to pass through. Using the same system as last time, we will pass through these two devices:

     

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

    01:03.0 Multimedia audio controller: C-Media Electronics Inc CMI8788 [Oxygen HD Audio]

     

    The /boot/extlinux.conf file should be edited the same as before, except that we separate each device’s number with a space, e.g.:

     

    pciback.hide=(03:00.0) (01:03.0)

     

    You can keep on adding more devices if you have more to pass through in the same fashion. Follow the rest of the instructions, and when it comes to adding them to the VM configuration you can do it like so:

     

    xe vm-param-set other-config:pci=0/0000:03:00.0,0/0000:01:03.0 uuid=[uuid]

     

    Note that there is only a comma, no space between the PCI addresses. That’s it!

  • Ubuntu: Using tar to span a backup across multiple tapes

     

    Following on from the article on writing files to a tape backup, what happens if you want to back up more than what fits on a single tape? Here we want to use the –multi-volume switch, or -M. Use it so:

     

    tar -cvMf /dev/[path-to-tape] [backup folder or files]

     

    As a working example:

     

    tar -cvMf /dev/st0 /opt/movies

     

    Once the first tape is full, tar will prompt you to insert another:

     

    Prepare volume #2 for `/dev/st0′ and hit return:

     

    Make sure you replace the tape with another before hitting return or else it will over-write the just-finished tape!

     

    With the exception of a file which sits across multiple tapes (think of a file which starts at the end of one tapes and finishes at the start of the next) you don’t need a first tape to restore the files on the second. You also cannot use compression for multi-volume archives.