安装RAC clusterware时，有两项没有通过检查，提示信息如下：
Checking local Cluster Synchronization Services (CSS) status ...
Actual Result: Unknown Host Exception has Occurred :10.3.83.25.
Check complete. The overall result of this check is: Not executed <<<<
Recommendation: Cluster Synchronization Services (CSS) provide services for single-instance Automatic Storage Management (ASM) in addition to being part of the Oracle Clusterware stack. When configured stand-alone outside of the Oracle Clusterware, it is sometimes referred to as "local" CSS.
Because you are installing Oracle Clusterware on a set of nodes that already have local CSS configured, you must shut down any ASM instances and any databases using ASM and deconfigure local CSS on those nodes before proceeding with the Oracle Clusterware installation. You can deconfigure local CSS by running 'localconfig delete' as the root user from OH/bin. After the Oracle Clusterware installation and configuration is complete, CSS will be started and configured to run from the Oracle Clusterware Home. You may then restart any ASM instances and any databases that use ASM.
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Checking whether Oracle 9.2 RAC is available on all selected nodes
Actual Result: Unknown Host Exception has Occurred :10.3.83.25.
Check complete. The overall result of this check is: Not executed <<<<
Recommendation: Make sure that all the nodes are a part of Oracle 9.2 RAC environment before you install Oracle Clusterware 10g Release 2.
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此错误与hostname和hosts相关，检查相关配置文件。
[root@rac1 ~]# more /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=no
HOSTNAME=rac1
GATEWAY=10.3.83.126
[root@rac1 ~]# hostname
rac1
[root@rac1 ~]# more /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 rac1.localdomain localhost
::1 localhost6.localdomain6 localhost6
10.3.83.25 rac1.localdomain rac1
10.3.83.27 rac1-vip.localdomain rac1-vip
192.168.100.11 rac1-priv.localdomain rac1-priv
10.3.83.26 rac2.localdomain rac2
10.3.83.28 rac2-vip.localdomain rac2-vip
192.168.100.22 rac2-priv.localdomain rac2-priv
[root@rac2 ~]# more /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=no
HOSTNAME=rac2
GATEWAY=10.3.83.126
[root@rac2 ~]# hostname
rac2
[root@rac2 ~]# more /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 rac2.localdomain localhost
::1 localhost6.localdomain6 localhost6
10.3.83.25 rac1.localdomain rac1
10.3.83.27 rac1-vip.localdomain rac1-vip
192.168.100.11 rac1-priv.localdomain rac1-priv
10.3.83.26 rac2.localdomain rac2
10.3.83.28 rac2-vip.localdomain rac2-vip
192.168.100.22 rac2-priv.localdomain rac2-priv
没有发现什么异常情况，直接把hosts改为如下，问题解决：
[root@rac1 ~]# more /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 rac1.localdomain localhost
::1 localhost6.localdomain6 localhost6
10.3.83.25 rac1
10.3.83.27 rac1-vip
192.168.100.11 rac1-priv
10.3.83.26 rac2
10.3.83.28 rac2-vip
192.168.100.22 rac2-priv