'Return vdisk attributes or None if it doesn\'t exist.'

def lsvdisk(self, vdisk):

    ssh_cmd = ['svcinfo', 'lsvdisk', '-bytes', '-delim', '!', ('"%s"' % vdisk)]
    (out, err) = self._ssh(ssh_cmd, check_exit_code=False)
    if (not err):
        return CLIResponse((out, err), ssh_cmd=ssh_cmd, delim='!', with_header=False)[0]
    if ('CMMVC5754E' in err):
        return None
    msg = (_('CLI    Exception    output:\n    command:    %(cmd)s\n    stdout:    %(out)s\n    stderr:    %(err)s.') % {'cmd': ssh_cmd, 'out': out, 'err': err})
    LOG.error(msg)
    raise exception.VolumeBackendAPIException(data=msg)
