如果已设置RAT_UPGRADE_LOC但不想升级，则仍可以使用-noupgrade选项运行Oracle ORAchk：
[grid@rac2 orachk]$./orachk –noupgrade4）升级后检查s
[grid@rac2 orachk]$./orachk -u -o post1.4. 执行ORAchk检查1.4.1. 单实例执行ORAchk检查[root@host1 orachk]# ./orachkChecking ssh user equivalency settings on all nodes in cluster for rootList of running databases1. cndba2. None of aboveSelect databases from list for checking best practices. For multiple databases, select 1 for All or comma separated number like 1,2 etc [1-2][1]. 1. .Checking Status of Oracle Software Stack - Clusterware, ASM, RDBMS. . . . . . . . . . .. . . . . . . . . . .-------------------------------------------------------------------------------------------------------Oracle Stack Status-------------------------------------------------------------------------------------------------------Host Name CRS Installed ASM HOME RDBMS Installed CRS UP ASM UP RDBMS UP DB Instance Name-------------------------------------------------------------------------------------------------------host1 No No Yes No No Yes cndba-------------------------------------------------------------------------------------------------------Copying plug-ins. .. . . . . .*** Checking Best Practice Recommendations ( PASS / WARNING / FAIL ) ***. .Collections and audit checks log file is/orachk/orachk_host1_PDBCNDBA_072518_100235/log/orachk.log============================================================Node name - host1============================================================……--------------------------------------------------------------------------------RDBMS homes patches summary report--------------------------------------------------------------------------------Total patches Applied on RDBMS Applied on ASM ORACLE_HOME--------------------------------------------------------------------------------1 1 0 /u01/app/oracle/product/18.1.0/dbhome_1--------------------------------------------------------------------------------------------------------------------------------------------Detailed report (html) - /orachk/orachk_host1_PDBCNDBA_072518_100235/orachk_host1_PDBCNDBA_072518_100235.htmlUPLOAD [if required] - /orachk/orachk_host1_PDBCNDBA_072518_100235.zipORAchk 检查完成之后会生成一个html报告，这个报告的命名为：orachk_节点名_数据库名_时间.html，比如
orachk_host1_PDBCNDBA_072518_100235.html 。同时，它还会把所有的输出文件都打包为一个.zip文件，比如orachk_host1_PDBCNDBA_072518_100235.zip，可以把这个.zip文件从RAC服务器上下载到本地的windows，解压后查看其中的生成的orachk_节点名_数据库名_时间.html 这一个文件就可以 。
生成的报告也非常简单、清晰，在报告最上部会列出这次检查的分数，满分是100分 。
1.5. rac 执行ORAchk检查ORAchk会自动识别CRS HOME，请用户确认（当然，检查单实例就没有这个问题了），还会提问是检查集群中的哪个数据库 。因为RAC的所有实例的主机都会执行检查，如果以前没有配置过root用户的用户等效性，还会自动帮你配置，也都比较简单，跟着提示做就可以 。
[root@rac2 orachk]# ./orachkClusterware stack is running from /u01/app/18.1.0/grid. Is this the correct Clusterware Home?[y/n][y]Checking ssh user equivalency settings on all nodes in cluster for rootNode rac1 is not configured for ssh user equivalency and the orachk uses ssh to execute checks on remote nodes.Without passwordless ssh orachk can not run audit checks on the remote nodes.If necessary due to security policies the orachk can be run on each node using -localonly option.Do you want to configure SSH for user root on rac1 [y/n][y] yEnter rac1 root password :Verifying root password ...Node rac1 has been configured for ssh user equivalency for rootSearching for running databases . . . . .. .List of running databases registered in OCR1. cndba2. None of aboveSelect databases from list for checking best practices. For multiple databases, select 1 for All or comma separated number like 1,2 etc [1-2][1]. 1. . . .Checking Status of Oracle Software Stack - Clusterware, ASM, RDBMS. . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-------------------------------------------------------------------------------------------------------Oracle Stack Status-------------------------------------------------------------------------------------------------------Host Name CRS Installed RDBMS Installed CRS UP ASM UP RDBMS UP DB Instance Name-------------------------------------------------------------------------------------------------------rac2 Yes Yes Yes Yes Yes cndba2rac1 Yes Yes Yes Yes Yes cndba1-------------------------------------------------------------------------------------------------------Copying plug-ins. .. . . . . .*** Checking Best Practice Recommendations ( PASS / WARNING / FAIL ) ***. .Collections and audit checks log file is/orachk/orachk_rac2_CNDBAPDB_072518_101258/log/orachk.logStarting to run orachk in background on rac1============================================================Node name - rac2============================================================……------------------------------------------------------------CLUSTERWIDE CHECKS------------------------------------------------------------------------------------------------------------------------Detailed report (html) - /orachk/orachk_rac2_CNDBAPDB_072518_101258/orachk_rac2_CNDBAPDB_072518_101258.htmlUPLOAD [if required] - /orachk/orachk_rac2_CNDBAPDB_072518_101258.zip