配置11gR2 RAC SCAN
11G RAC scan即用DNA解析的IP地址，oracle推荐配置3个，这样可以起到均衡负载和冗余的作用.
系统情况： rac01,rac02
操作系统平台：red hat enterprise 5.4 2台虚拟机
这里 我们需要配置一个scan为 rac-scan的域名解析
配置步骤如下：
1. 我们设置rac01为DNS服务器
[root@rac01 etc]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:B5:38:5E
inet addr:192.168.0.18 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:feb5:385e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2332291 errors:0 dropped:0 overruns:0 frame:0
TX packets:1535201 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2347536563 (2.1 GiB) TX bytes:1079658292 (1.0 GiB)
Interrupt:185 Base address:0x1480
eth0:1 Link encap:Ethernet HWaddr 00:0C:29:B5:38:5E
inet addr:192.168.0.101 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:185 Base address:0x1480
eth1 Link encap:Ethernet HWaddr 00:0C:29:B5:38:68
inet addr:10.10.10.1 Bcast:10.10.10.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:feb5:3868/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:39950 errors:0 dropped:0 overruns:0 frame:0
TX packets:61611 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:15381230 (14.6 MiB) TX bytes:46112067 (43.9 MiB)
Interrupt:193 Base address:0x1800
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:54304 errors:0 dropped:0 overruns:0 frame:0
TX packets:54304 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:10332630 (9.8 MiB) TX bytes:10332630 (9.8 MiB)
从以上可以看出rac01的IP地址为:192.168.0.1
然后 配置 DNS named.conf 文件
[root@rac01 named]# vi /var/named/chroot/etc/named.conf
options {
listen-on port 53 { any; };
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";
query-source port 53;
query-source-v6 port 53;
allow-query { any; };
};
zone "." IN {
type hint;
file "named.ca";
};
zone "testenv.com" IN {
type master;
file "testenv.com.zone";
allow-update { none; };
};
zone "0.168.192.in-addr.arpa." IN {
type master;
file "0.168.192.in-addr.arpa.zone";
allow-update { none; };
};
"/var/named/chroot/etc/named.conf" 29L, 697C
[root@rac01 etc]# dig -t NS .
; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5 <<>> -t NS .
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14850
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14
;; QUESTION SECTION:
;. IN NS
;; ANSWER SECTION:
. 513716 IN NS e.root-servers.net.
. 513716 IN NS f.root-servers.net.
. 513716 IN NS g.root-servers.net.
. 513716 IN NS h.root-servers.net.
. 513716 IN NS i.root-servers.net.
. 513716 IN NS j.root-servers.net.
. 513716 IN NS k.root-servers.net.
. 513716 IN NS l.root-servers.net.
. 513716 IN NS m.root-servers.net.
. 513716 IN NS a.root-servers.net.
. 513716 IN NS b.root-servers.net.
. 513716 IN NS c.root-servers.net.
. 513716 IN NS d.root-servers.net.
;; ADDITIONAL SECTION:
a.root-servers.net. 600116 IN A 198.41.0.4
a.root-servers.net. 600116 IN AAAA 2001:503:ba3e::2:30
b.root-servers.net. 600116 IN A 192.228.79.201
c.root-servers.net. 600116 IN A 192.33.4.12
d.root-servers.net. 600116 IN A 128.8.10.90
e.root-servers.net. 600116 IN A 192.203.230.10
f.root-servers.net. 600116 IN A 192.5.5.241
f.root-servers.net. 600116 IN AAAA 2001:500:2f::f
g.root-servers.net. 600116 IN A 192.112.36.4
h.root-servers.net. 600116 IN A 128.63.2.53
h.root-servers.net. 600116 IN AAAA 2001:500:1::803f:235
i.root-servers.net. 600116 IN A 192.36.148.17
i.root-servers.net. 600116 IN AAAA 2001:7fe::53
j.root-servers.net. 600116 IN A 192.58.128.30
;; Query time: 7 msec
;; SERVER: 192.168.0.18#53(192.168.0.18)
;; WHEN: Sun Jan 2 09:09:56 2011
;; MSG SIZE rcvd: 500
[root@rac01 etc]# dig -t NS . >/var/named/named.ca
配置正解析文件
[root@rac01 etc]# vi /var/named/chroot/var/named/testenv.com.zone
$TTL 86400
@ IN SOA dns.testenv.com. root.dns.testenv.com. (
20110102
1H
15M
1W
1D)
testenv.com. IN NS dns.testenv.com.
dns IN A 192.168.0.18
www IN A 192.168.0.199
vip-rac01 IN A 192.168.0.100
vip-rac02 IN A 192.168.0.101
rac-scan IN A 192.168.0.55
rac-scan IN A 192.168.0.56
rac-scan IN A 192.168.0.57
news IN CNAME www
~
~
~
~
"/var/named/chroot/var/named/testenv.com.zone" 18L, 595C written
配置反解析文件
[root@rac01 etc]# vi /var/named/chroot/var/named/0.168.192.in-addr.arpa.zone
$TTL 86400
@ IN SOA dns.testenv.com. root.dns.testenv.com. (
20111102
3H
1H
1W
1H )
IN NS dns.testenv.com.
18 IN PTR dns.testenv.com.
199 IN PTR www.testenv.com.
100 IN PTR vip-rac01.testenv.com.
101 IN PTR vip-rac02.testenv.com.
55 IN PTR rac-scan.testenv.com.
56 IN PTR rac-scan.testenv.com.
57 IN PTR rac-scan.testenv.com.
~
~
~
~
"/var/named/chroot/var/named/0.168.192.in-addr.arpa.zone" 15L, 468C
配置DNS服务器所在地址：其中192.168.0.1为总的解析服务器,这里我们添加192.168.0.18为解析服务器
[root@rac01 etc]# vi /etc/resolv.conf
nameserver 192.168.0.18
nameserver 192.168.0.1
search localdomain testenv.com
~
~
"/etc/resolv.conf" 3L, 78C
配置hosts解析顺序:
[root@rac01 etc]# vi /etc/nsswitch.conf
#
# /etc/nsswitch.conf
#
# An example Name Service Switch config file. This file should be
# sorted with the most-used services at the beginning.
#
# The entry '[NOTFOUND=return]' means that the search for an
# entry should stop if the search in the previous entry turned
# up nothing. Note that if the search failed due to some other reason
# (like no NIS server responding) then the search continues with the
# next entry.
#
# Legal entries are:
#
# nisplus or nis+ Use NIS+ (NIS version 3)
# nis or yp Use NIS (NIS version 2), also called YP
# dns Use DNS (Domain Name Service)
# files Use the local files
# db Use the local database (.db) files
# compat Use NIS on compat mode
# hesiod Use Hesiod for user lookups
# [NOTFOUND=return] Stop searching if not found so far
#
# To use db, put the "db" in front of "files" for entries you want to be
# looked up first in the databases
#
# Example:
#passwd: db files nisplus nis
#shadow: db files nisplus nis
#group: db files nisplus nis
passwd: files
shadow: files
group: files
#hosts: db files nisplus nis dns
#hosts: files dns
hosts: dns files nis
# Example - obey only what nisplus tells us...
#services: nisplus [NOTFOUND=return] files
"/etc/nsswitch.conf" 64L, 1724C
然后重新启动DNS服务
[root@rac01 etc]# service named restart
Stopping named: [ OK ]
Starting named: [ OK ]
[root@rac01 etc]# tail /var/log/messages
Jan 2 09:14:02 rac01 named[29179]: listening on IPv4 interface eth0:1, 192.168.0.101#53
Jan 2 09:14:02 rac01 named[29179]: listening on IPv4 interface eth1, 10.10.10.1#53
Jan 2 09:14:02 rac01 named[29179]: /etc/named.conf:8: using specific query-source port suppresses port randomization and can be insecure.
Jan 2 09:14:02 rac01 named[29179]: /etc/named.conf:9: using specific query-source port suppresses port randomization and can be insecure.
Jan 2 09:14:02 rac01 named[29179]: command channel listening on 127.0.0.1#953
Jan 2 09:14:02 rac01 named[29179]: command channel listening on ::1#953
Jan 2 09:14:02 rac01 named[29179]: the working directory is not writable
Jan 2 09:14:02 rac01 named[29179]: zone 0.168.192.in-addr.arpa/IN: loaded serial 20111102
Jan 2 09:14:02 rac01 named[29179]: zone testenv.com/IN: loaded serial 20110102
Jan 2 09:14:02 rac01 named[29179]: running
检查配置是否成功：试着解析rac-scan域名
[root@rac01 etc]# nslookup rac-scan
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: rac-scan.testenv.com
Address: 192.168.0.55
Name: rac-scan.testenv.com
Address: 192.168.0.56
Name: rac-scan.testenv.com
Address: 192.168.0.57
[root@rac01 etc]# nslookup vip-rac01
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: vip-rac01.testenv.com
Address: 192.168.0.100
[root@rac01 etc]# nslookup vip-rac02
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: vip-rac02.testenv.com
Address: 192.168.0.101
反解析：
[root@rac01 etc]# nslookup 192.168.0.56
Server: 192.168.0.18
Address: 192.168.0.18#53
56.0.168.192.in-addr.arpa name = rac-scan.testenv.com.
[root@rac01 etc]#
看来配置成功!
然后再在rac02上做相关配置:
[root@rac02 ~]# vi /etc/nsswitch.conf
#
# /etc/nsswitch.conf
#
# An example Name Service Switch config file. This file should be
# sorted with the most-used services at the beginning.
#
# The entry '[NOTFOUND=return]' means that the search for an
# entry should stop if the search in the previous entry turned
# up nothing. Note that if the search failed due to some other reason
# (like no NIS server responding) then the search continues with the
# next entry.
#
# Legal entries are:
#
# nisplus or nis+ Use NIS+ (NIS version 3)
# nis or yp Use NIS (NIS version 2), also called YP
# dns Use DNS (Domain Name Service)
# files Use the local files
# db Use the local database (.db) files
# compat Use NIS on compat mode
# hesiod Use Hesiod for user lookups
# [NOTFOUND=return] Stop searching if not found so far
#
# To use db, put the "db" in front of "files" for entries you want to be
# looked up first in the databases
#
# Example:
#passwd: db files nisplus nis
#shadow: db files nisplus nis
#group: db files nisplus nis
passwd: files
shadow: files
group: files
#hosts: db files nisplus nis dns
#hosts: files dns
hosts: dns files nis
# Example - obey only what nisplus tells us...
#services: nisplus [NOTFOUND=return] files
"/etc/nsswitch.conf" 64L, 1722C
[root@rac02 ~]# vi /etc/resolv.conf
; generated by /sbin/dhclient-script
nameserver 192.168.0.18
nameserver 192.168.0.1
search localdomain testenv.com
~
~
"/etc/resolv.conf" 4L, 115C
[root@rac02 ~]# nslookup rac-scan
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: rac-scan.testenv.com
Address: 192.168.0.56
Name: rac-scan.testenv.com
Address: 192.168.0.57
Name: rac-scan.testenv.com
Address: 192.168.0.55
[root@rac02 ~]#
[root@rac02 ~]# nslookup vip-rac01
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: vip-rac01.testenv.com
Address: 192.168.0.100
[root@rac02 ~]# nslookup vip-rac02
Server: 192.168.0.18
Address: 192.168.0.18#53
Name: vip-rac02.testenv.com
Address: 192.168.0.101
[root@rac02 ~]# nslookup 192.168.0.56
Server: 192.168.0.18
Address: 192.168.0.18#53
56.0.168.192.in-addr.arpa name = rac-scan.testenv.com.
[root@rac02 ~]#
rac02也可以正确解析SCAN域名！
这样一个正反解析的SCAN域名就配置成功了.......
注意：在安装11Gr2 RAC集群时，配置其中的一个节点作为DNS服务器是不被支持的，安装过程中会出错