RAC增加节点：
环境：
OS：OEL5.6
RAC：10.2.0.1.0
原有rac1,rac2两个节点，现在要增加rac3节点：
操作过程：
修改三个节点上的/etc/hosts文件
192.168.90.2 rac1
192.168.90.5 rac2
192.168.90.6 rac3
192.168.91.3 rac1-priv
192.168.91.6 rac2-priv
192.168.91.7 rac3-priv
192.168.90.3 rac1-vip
192.168.90.4 rac2-vip
192.168.90.7 rac3-vip
rac3节点上安装需要的rpm包，本实验环境使用的是OEL系统，所以使用oracle-validated。
[root@rac3 ~]# mount /dev/cdrom /mnt
mount: block device /dev/cdrom is write-protected, mounting read-only
[root@rac3 ~]# vi /etc/yum.repos.d/public-yum-el5.repo
[oel5]
name = Enterprise Linux 5.6 DVD
baseurl=file:///mnt/Server/
gpgcheck=0
enabled=1
[root@rac3 ~]# yum install oracle-validated
Loaded plugins: rhnplugin, security
This system is not registered with ULN.
ULN support will be disabled.
......略
安装ASMLib包：
[root@rac3 ~]# cd /mnt/Server
[root@rac3 Server]# rpm -ivh oracleasm-support-2.1.4-1.el5.i386.rpm
warning: oracleasm-support-2.1.4-1.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing... ########################################### [100%]
1:oracleasm-support ########################################### [100%]
[root@rac3 Server]# rpm -ivh oracleasm-2.6.18-238.el5-2.0.5-1.el5.i686.rpm
warning: oracleasm-2.6.18-238.el5-2.0.5-1.el5.i686.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing... ########################################### [100%]
1:oracleasm-2.6.18-238.el########################################### [100%]
配置3节点和1,2节点间的互信：
3节点：
[oracle@rac3 ~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/oracle/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/oracle/.ssh/id_rsa.
Your public key has been saved in /home/oracle/.ssh/id_rsa.pub.
The key fingerprint is:
18:d5:6a:94:4c:12:90:8a:19:ca:96:4d:97:cc:fe:f0 oracle@rac3
1节点：
[oracle@rac1 .ssh]$ ssh 192.168.90.6 cat ~/.ssh/*.pub >> authorized_keys
oracle@192.168.90.6's password:
[oracle@rac1 .ssh]$ scp authorized_keys 192.168.90.6:~/.ssh/.
oracle@192.168.90.6's password:
authorized_keys 100% 1780 1.7KB/s 00:00
[oracle@rac1 .ssh]$ scp authorized_keys 192.168.90.5:~/.ssh/.
authorized_keys 100% 1780 1.7KB/s 00:00
各个节点执行以下脚本测试oracle用户的互信：
ssh rac1 date
ssh rac2 date
ssh rac3 date
ssh rac1-priv date
ssh rac2-priv date
ssh rac3-priv date
配置时间同步：
[root@rac3 Server]# ntpdate 192.168.90.2
22 Aug 10:45:31 ntpdate[9511]: adjust time server 192.168.90.2 offset -0.109663 sec
[root@rac3 Server]# crontab -e
* * * * * /usr/sbin/ntpdate 192.168.90.2 >> /ntp.log
由于使用的是openfiler作为存储，这里添加openfiler配置过程：
然后到rac3节点上配置：
[root@rac3 ~]# vi /etc/iscsi/initiatorname.iscsi
#InitiatorName=iqn.1988-12.com.oracle:48354521e5f2
InitiatorName=rac3
[root@rac3 ~]# iscsiadm -m discovery -t st -p 192.168.90.8
192.168.90.8:3260,1 rac3
[root@rac3 ~]# service iscsi restart
Stopping iSCSI daemon:
iscsid is stopped [ OK ]
Starting iSCSI daemon: [ OK ]
[ OK ]
Setting up iSCSI targets: Logging in to [iface: default, target: rac3, portal: 192.168.90.8,3260]
Login to [iface: default, target: rac3, portal: 192.168.90.8,3260] successful.
[ OK ]
然后看一下磁盘是否挂载成功：
[root@rac3 ~]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylin