https://blog.csdn.net/wuweilong/article/details/8506566
问题现象：
Grid安装到最后一步，两边的root脚本也执行完了，撂出个INS-20802错误，从错误现象来看，看不出什么问题，提示查看.log文件。

Log文件内容：

INFO: Checking Single ClientAccess Name (SCAN)...
INFO: Checking name resolution setup for "SCAN"...
INFO: ERROR:
INFO: PRVF-4664 : Found inconsistent name resolution entries for SCAN name"SCAN"
INFO: ERROR:
INFO: PRVF-4657 : Name resolution setup check for "SCAN" (IP address:172.16.9.150) failed
INFO: ERROR:
INFO: PRVF-4664 : Found inconsistent name resolution entries for SCAN name"SCAN"
INFO: Verification of SCAN VIP and Listener setup failed

问题分析：

通过参考Metalink[ID887471]文章得出以下结论：

http://www.prudentwoo.com/archives/730

http://space.itpub.net/?uid-20674423-action-viewspace-itemid-752693

http://blog.csdn.net/wuweilong/article/details/8505806

由于配置了/etc/hosts来解析SCAN，导致未走DNS来进行SCAN的解析，爆出此错误，可以考虑忽略掉，或者删除/etc/hosts文件中的SCAN解析部分，并且再次通过nslookup验证DNS的解析是否正常即可。