作为集群，oracle cluster需要共享存储来存放整个集群的配置信息，ocr便是用例存放这些配置信息的地方，ocr的存储容量一般不会太
ocr和votedisk是什么？
作为集群，Oracle cluster需要共享存储来存放整个集群的配置信息，ocr便是用例存放这些配置信息的地方，ocr的存储容量一般不会太大，在10g下，oracle建议256M已经足以。ocr必须需要存储在集群文件系统或者裸设备上，出于性能上的考虑，本人建议将ocr建立在裸设备上，性能高并且管理也不复杂（ocr和votedisk的数量一般不会太多）。ocr中存放的是集群的配置信息，这些信息只能在一个节点上进行维护操作，这一节点叫做Master Node，其他节点会在内存中保留一份ocr的复制，并且只能进行读操作，所有ocr的更新都是有master node来执行并通知各个节点的。
votedisk磁盘存储集中地各个节点并用来进行心跳监测
ocr和votedisk的维护是否需要保持脱机状态？
orc的维护在大多数情况下，是需要联机操作的，因为在各个节点具有ocr.loc文件，联机操作可以保证各个节点的ocr.loc文件及时得到更新。但是部分操作，如repaire和重建等操作需要在脱机状态下进行（后面会详细描述）
votedisk磁盘的维护往往需要在脱机状态下进行
Oracle 11g 在RedHat Linux 5.8_x64平台的安装手册
Linux-6-64下安装Oracle 12C笔记
在CentOS 6.4下安装Oracle 11gR2(x64)
Oracle 11gR2 在VMWare虚拟机中安装步骤
Debian 下 安装 Oracle 11g XE R2
ocr维护的命令有哪些？
维护ocr常用的命令有：
ocrcheck
[root@node1 bin]# ./ocrcheck -h
Name:
ocrcheck - Displays health of Oracle Cluster Registry.
Synopsis:
ocrcheck
Description:
prompt> ocrcheck
Displays current usage, location and health of the cluster registry
Notes:
A log file will be created in
$ORACLE_HOME/log/
you have file creation privileges in the above directory before
running this tool.
ocrdump（dump出来的内容可以用来查看ocr中的内容，但是不可以用来进行恢复）
[root@node1 bin]# ./ocrdump -h
Name:
ocrdump - Dump contents of Oracle Cluster Registry to a file.
Synopsis:
ocrdump [
Description:
Default filename is OCRDUMPFILE. Examples are:
prompt> ocrdump
writes cluster registry contents to OCRDUMPFILE in the current directory
prompt> ocrdump MYFILE
writes cluster registry contents to MYFILE in the current directory
prompt> ocrdump -stdout -keyname SYSTEM
writes the subtree of SYSTEM in the cluster registry to stdout
prompt> ocrdump -stdout -xml
writes cluster registry contents to stdout in xml format
Notes:
The header information will be retrieved based on best effort basis.
A log file will be created in
$ORACLE_HOME/log/
you have file creation privileges in the above directory before
running this tool.
ocrconfig
[root@node1 bin]# ./ocrconfig -h
Name:
ocrconfig - Configuration tool for Oracle Cluster Registry.
Synopsis:
ocrconfig [option]
option:
-export
- Export cluster register contents to a file
-import
-upgrade [
- Upgrade cluster registry from previous version
-downgrade [-version
- Downgrade cluster registry to the specified version
-backuploc
-showbackup - Show backup information
-restore
-replace ocr|ocrmirror [
-overwrite - Overwrite OCR configuration on disk
-repair ocr|ocrmirror
-help - Print out this help information
Note:
A log file will be created in
$ORACLE_HOME/log/
you have file creation privileges in the above directory before
running this tool.
Table D-1 The ocrconfig Command Options
OptionPurpose
-backuploc
To change an OCR backup file location. For this entry, use a full path that is accessible by all of the nodes.
-downgrade
To downgrade an OCR to an earlier version.
-export
To export the contents of an OCR into a target file.
-help
To display help for the ocrconfig commands.
-import
To import the OCR contents from a previously exported OCR file.
-overwrite
To update an OCR configuration that is recorded on the OCR with the current OCR configuration information that is found on the node from which you are running this command.
-repair
To update an OCR configuration on the node from which you are running this command with the new configuration information specified by this command.
-replace
To add, replace, or remove an OCR location.
-restore
To restore an OCR from an automatically created OCR backup file.
-showbackup
