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.comsearch     racdb.comnameserver 192.168.1.111

检查配置文件

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

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

[root@linux named]# service named restartStopping 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 startStarting named: [  OK  ]

[root@linux named]# chkconfig named on 

[root@linux named]# nslookup racscanServer:     192.168.1.111Address:    192.168.1.111#53Name:   racscan.racdb.comAddress: 192.168.1.198Name:   racscan.racdb.comAddress: 192.168.1.200Name:   racscan.racdb.comAddress: 192.168.1.199

反向解析：

[root@linux named]# nslookup 192.168.1.200Server:     192.168.1.111Address:    192.168.1.111#53200.1.168.192.in-addr.arpa  name = racscan.

[root@linux named]# nslookup 192.168.1.199Server:     192.168.1.111Address:    192.168.1.111#53199.1.168.192.in-addr.arpa  name = racscan.

[root@linux named]# nslookup 192.168.1.198Server:     192.168.1.111Address:    192.168.1.111#53198.1.168.192.in-addr.arpa  name = racscan.