OpenNebula

        'XM_INFO' => 'sudo /usr/sbin/xm info',

        'XM_POLL_XEN_3' => 'sudo /usr/sbin/xentop -bi2',

        'XM_POLL_XEN_4' => 'sudo /usr/sbin/xentop -fbi1'

    def self.get_xen_version

    begin

        xen_major=`sudo /usr/sbin/xm info |awk '/xen_major/{print $3}'`.to_i

        xen_minor=`sudo /usr/sbin/xm info |awk '/xen_minor/{print $3}'`.to_i

        xen_extra=`sudo /usr/sbin/xm info |awk '/xen_minor/{print $3}'`.delete('.').to_i

        return [xen_major, xen_minor, xen_extra]

    rescue

        STDERR.puts "Failed to get Xen version, assuming 3.0.0"

        return [3, 0, 0]

    end

    end

        # The arguments to xentop change depending on the xentop version.

        # The headers are not repeated by default in Xen 4.0.1, unless the -f

        # option is specified. Older versions of Xentop do not have a -f flag.

        version = get_xen_version

        if version[0] <= 3 then

            text=`#{CONF['XM_POLL_XEN_3']}`

            lines=text.strip.split("\n")

            block_size=lines.length/2

            valid_lines=lines.last(block_size)

            domain_lines=valid_lines[4..-1]

        else

            text=`#{CONF['XM_POLL_XEN_4']}`

            lines=text.strip.split("\n")

            domain_lines=lines.last(lines.length - 1)

        end

	[]