oracle11g rac环境搭建中linux DNS Server搭建

安装oracle 11g rac时SCAN IP需要进行DNS解析，在没有外部DNS服务器的情况下，在数据库服务器（linux）上部署DNS Server，进行DNS解析SCAN IP。

数据库服务器保证DNS解析具有冗余性，DNS server部署在每个节点上，互为备用模式。

node1优先通过node1的DNS服务器解析SCAN域名，如果DNS服务出现问题，下一跳通过node2的DNS服务器进行DNS解析。
node2优先通过node2的DNS服务器解析SCAN域名，如果DNS服务出现问题，下一跳通过node1的DNS服务器进行DNS解析。

//安装DNS

RHEL 6.4 安装DNS服务（bind-9.8 ）

首先安装yum，使用yum安装bind

yum install bind*

不同的操作系统rpm包有可能会不同

bind-9.8.2-0.17.rc1.el6.x86_64
bind-utils-9.8.2-0.17.rc1.el6.x86_64
bind-chroot-9.8.2-0.17.rc1.el6.x86_64
bind-dyndb-ldap-2.3-2.el6.x86_64
bind-libs-9.8.2-0.17.rc1.el6.x86_64

几个rpm包安装之后，编辑named.conf

//配置

[root@linux named]# vi /etc/named.conf

//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//

options {
listen-on port 53 { any; };  //修改
listen-on-v6 port 53 { ::1; };
directory   "/var/named";
dump-file   "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query     { any; };    //修改
allow-query-cache { any; };  //修改
recursion yes;

dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside auto;

/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";

managed-keys-directory "/var/named/dynamic";
};

logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
//新增如下记录
zone "racdb.com" IN {
type master;
file "named.racdb.com";

};

zone "1.168.192.in-addr.arpa" IN {
type master;
file "named.192.168.1";
};
include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";

[root@linux named]# cd /var/named

[root@linux named]# vi named.racdb.com

$TTL 1D
@   IN SOA  @ root.racdb.com. (
0   ; serial
1D  ; refresh
1H  ; retry
1W  ; expire
3H )    ; minimum
@       IN     NS       localhost.
racscan IN      A       192.168.1.200;
racscan IN      A       192.168.1.199;
racscan IN      A       192.168.1.198;

[root@linux named]# vi named.192.168.1

$TTL 3600
@      IN      SOA   racdb.com. root.racdb.com. (
2014102402
1H
5M
1w
1D )
@      IN      NS     racdb.com.
200     IN      PTR     racscan.
199     IN      PTR     racscan.
198     IN      PTR     racscan.

[root@linux named]# vi /etc/resolv.conf

# Generated by NetworkManager

# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
search     racdb.com
nameserver 192.168.1.111

检查配置文件

[root@linux named]# named-checkzone racdb.com named.racdb.com
zone racdb.com/IN: loaded serial 0
OK

[root@linux named]# named-checkzone 1.168.192.in-addr.arpa named.192.168.1
zone 1.168.192.in-addr.arpa/IN: loaded serial 2014102402
OK

[root@linux named]# service named restart
Stopping named:                                            [  OK  ]
Starting named:                                            [  OK  ]

在启动DNS时出现Generating /etc/rndc.key:卡在这里了，下面测试

[root@node1 named]# rndc-confgen -r /dev/urandom -a
wrote key file "/etc/rndc.key"
[root@node1 named]# service named start
Starting named: [  OK  ]

[root@linux named]# chkconfig named on

[root@linux named]# nslookup racscan
Server:     192.168.1.111
Address:    192.168.1.111#53

Name:   racscan.racdb.com
Address: 192.168.1.198
Name:   racscan.racdb.com
Address: 192.168.1.200
Name:   racscan.racdb.com
Address: 192.168.1.199

反向解析：

[root@linux named]# nslookup 192.168.1.200
Server:     192.168.1.111
Address:    192.168.1.111#53

200.1.168.192.in-addr.arpa  name = racscan.

[root@linux named]# nslookup 192.168.1.199
Server:     192.168.1.111
Address:    192.168.1.111#53

199.1.168.192.in-addr.arpa  name = racscan.

[root@linux named]# nslookup 192.168.1.198
Server:     192.168.1.111
Address:    192.168.1.111#53

198.1.168.192.in-addr.arpa  name = racscan.

a022