Synnefo » snf-ganeti

    Valid for the Xen, KVM and LXC hypervisors.

    The format of the mask can be given in three forms. First, the word

    "all", which signifies the common case where all VCPUs can live on

    any CPU, based on the hypervisor's decisions.

    Second, a comma-separated list of CPU IDs or CPU ID ranges. The

    ranges are defined by a lower and higher boundary, separated by a

    dash, and the boundaries are inclusive. In this form, all VCPUs of

    the instance will be mapped on the selected list of CPUs. Example:

    ``0-2,5``, mapping all VCPUs (no matter how many) onto physical CPUs

    0, 1, 2 and 5.

    The last form is used for explicit control of VCPU-CPU pinnings. In

    this form, the list of VCPU mappings is given as a colon (:)

    separated list, whose elements are the possible values for the

    second or first form above. In this form, the number of elements in

    the colon-separated list _must_ equal the number of VCPUs of the

    instance.

    Example::

      # Map the entire instance to CPUs 0-2

      gnt-instance modify -H cpu_mask=0-2 my-inst

      # Map vCPU 0 to physical CPU 1 and vCPU 1 to CPU 3 (assuming 2 vCPUs)

      gnt-instance modify -H cpu_mask=1:3 my-inst

      # Pin vCPU 0 to CPUs 1 or 2, and vCPU 1 to any CPU

      gnt-instance modify -H cpu_mask=1-2:all my-inst

      # Pin vCPU 0 to any CPU, vCPU 1 to CPUs 1, 3, 4 or 5, and CPU 2 to

      # CPU 0 (backslashes for escaping the comma)

      gnt-instance modify -H cpu_mask=all:1\\,3-5:0 my-inst

      # Pin entire VM to CPU 0

      gnt-instance modify -H cpu_mask=0 my-inst

      # Turn off CPU pinning (default setting)

      gnt-instance modify -H cpu_mask=all my-inst