def METHOD_NAME(self, disk):
    cmd = ['scu', '-f', disk, 'preserve', 'register', 'skey', '0', 'key', self.hostid]
    (ret, out, err) = self.vcall(cmd)
    if ret != 0:
        self.log.error("failed to unregister key %s with disk %s" % (self.hostid, disk))
    return ret