...
my ($now_vgname,$now_label);
while ( <$input_handle> ) {
    if ( /lsattr -El (\w+)/ ) 
		$now_vgname = $1;
		next;
	}
	if ( /label\s+([\/\w]+)/ ) {
		$now_label = $1;
		next;
	}
	if ( /lvserial_id\s+([\w\.]+)/ ) {
		$host_info{VG}->{$now_vgname}->{$1}->{LV} = $now_label
		next;
	}
}