'svctask expandvdisksize -size <size> -unit gb <vdisk_name>'

def _cmd_expandvdisksize(self, **kwargs):

    if ('obj' not in kwargs):
        return self._errors['CMMVC50000']
    vol_name = kwargs['obj'].strip('\'"')
    if ('size' not in kwargs):
        return self._errors['CMMVC50000']
    size = int(kwargs['size'])
    if (vol_name not in self._volumes_list):
        return self._errors['CMMVC50000']
    curr_size = int(self._volumes_list[vol_name]['capacity'])
    addition = (size * units.Gi)
    self._volumes_list[vol_name]['capacity'] = six.text_type((curr_size + addition))
    return ('', '')
