Oracle RAC hosts 文件格式：

[root@rac1 racg]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost
10.1.11.151 rac1
10.1.11.152 rac2

192.168.0.11 rac1-priv
192.168.0.12 rac2-priv

10.1.11.153 rac1-vip
10.1.11.154 rac2-vip
[root@rac1 racg]#

注意： 一定要有 127.0.0.1 localhost 一项，否则在配置完 ONS ， 启动 ONS 时， 会在日志文件 /u01/crs/log/rac1/racg/ora.rac1.ons.log 中报以下错误：

Oracle Database 10g CRS Release 10.2.0.1.0 Production Copyright 1996, 2005 Oracle. All rights reserved.
2011-10-10 09:35:06.728: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: Failed to get IP for localhost (1)
Failed to get IP for localhost (1)
Failed to get IP for localhost (1)
onsctl: ons failed to start

2011-10-10 09:35:06.728: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: clsrcexecut: env ORACLE_CONFIG_HOME=/u01/crs

2011-10-10 09:35:06.728: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: clsrcexecut: cmd = /u01/crs/bin/racgeut -e _USR_ORA_DEBUG=0 540 /u01/crs/bin/onsctl start

2011-10-10 09:35:06.728: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: clsrcexecut: rc = 1, time = 2.050s

2011-10-10 09:35:09.487: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: Failed to get IP for localhost (1)
ons is not running ...

2011-10-10 09:35:09.487: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: clsrcexecut: env ORACLE_CONFIG_HOME=/u01/crs

2011-10-10 09:35:09.487: [ RACG][31419680] [12990][31419680][ora.rac1.ons]: clsrcexecut: cmd = /u01/crs/bin/racgeut -e _USR_ORA_DEBUG=0 540 /u01/crs/bin/onsctl ping