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
在CentOS 6.4下安装Oracle 11gR2(x64)
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/<hostname>/client/ocrcheck_<pid>.log. Please ensure
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 [<filename>|-stdout] [-backupfile <backupfilename>] [-keyname <keyname>] [-xml] [-noheader]
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/<hostname>/client/ocrdump_<pid>.log. Make sure
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 <filename> [-s online]
- Export cluster register contents to a file
-import <filename> - Import cluster registry contents from a file
-upgrade [<user> [<group>]]
- Upgrade cluster registry from previous version
-downgrade [-version <version string>]
- Downgrade cluster registry to the specified version
-backuploc <dirname> - Configure periodic backup location
-showbackup - Show backup information
-restore <filename> - Restore from physical backup
-replace ocr|ocrmirror [<filename>] - Add/replace/remove a OCR device/file
-overwrite - Overwrite OCR configuration on disk
-repair ocr|ocrmirror <filename> - Repair local OCR configuration
-help - Print out this help information
Note:
A log file will be created in
$ORACLE_HOME/log/<hostname>/client/ocrconfig_<pid>.log. Please ensure
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
To display the location, timestamp, and the originating node name of the backup files that Oracle created in the past 4 hours, 8 hours, 12 hours, and in the last day and week. You do not have to be the root user to execute the -showbackup option.
-upgrade
To upgrade an OCR to a later version.
ocr损坏后怎么恢复？
ocr损坏后通常有两种方式进行修正：恢复和重建。恢复的时候，我们可以从之前export导出的文件恢复，也可以从之前有masternode备份的文件进行恢复。
[root@node1 bin]# ./crs_stat -t -v
Name Type R/RA F/FT Target State Host
----------------------------------------------------------------------
httpd_vip application 0/1 0/0 ONLINE ONLINE node2
httpd_web application 0/1 0/4 ONLINE ONLINE node2
ora....SM1.asm application 0/5 0/0 ONLINE ONLINE node1
ora....E1.lsnr application 0/5 0/0 ONLINE ONLINE node1
ora.node1.gsd application 0/5 0/0 ONLINE ONLINE node1
ora.node1.ons application 0/3 0/0 ONLINE ONLINE node1
ora.node1.vip application 0/0 0/0 ONLINE ONLINE node1
ora....SM2.asm application 0/5 0/0 ONLINE ONLINE node2
ora....E2.lsnr application 0/5 0/0 ONLINE ONLINE node2
ora.node2.gsd application 0/5 0/0 ONLINE ONLINE node2
ora.node2.ons application 0/3 0/0 ONLINE ONLINE node2
ora.node2.vip application 0/0 0/0 ONLINE ONLINE node2
ora.racdb.db application 0/0 0/1 ONLINE ONLINE node2
ora....b1.inst application 0/5 0/0 ONLINE ONLINE node1
ora....b2.inst application 0/5 0/0 ONLINE ONLINE node2
[root@node1 bin]# ./ocrconfig -export a.ocr （导出时最好是关闭crs）
[root@node1 bin]# ./crs_stop httpd_web
Attempting to stop `httpd_web` on member `node2`
Stop of `httpd_web` on member `node2` succeeded.
[root@node1 bin]# ./crs_stop httpd_vip
Attempting to stop `httpd_vip` on member `node2`
Stop of `httpd_vip` on member `node2` succeeded.
[root@node1 bin]# ./crs_stat -t -v
Name Type R/RA F/FT Target State Host
----------------------------------------------------------------------
httpd_vip application 0/1 0/0 OFFLINE OFFLINE
httpd_web application 0/1 0/4 OFFLINE OFFLINE
ora....SM1.asm application 0/5 0/0 ONLINE ONLINE node1
ora....E1.lsnr application 0/5 0/0 ONLINE ONLINE node1
ora.node1.gsd application 0/5 0/0 ONLINE ONLINE node1
ora.node1.ons application 0/3 0/0 ONLINE ONLINE node1
ora.node1.vip application 0/0 0/0 ONLINE ONLINE node1
ora....SM2.asm application 0/5 0/0 ONLINE ONLINE node2
ora....E2.lsnr application 0/5 0/0 ONLINE ONLINE node2
ora.node2.gsd application 0/5 0/0 ONLINE ONLINE node2
ora.node2.ons application 0/3 0/0 ONLINE ONLINE node2
ora.node2.vip application 0/0 0/0 ONLINE ONLINE node2
ora.racdb.db application 0/0 0/1 ONLINE ONLINE node2
ora....b1.inst application 0/5 0/0 ONLINE ONLINE node1
ora....b2.inst application 0/5 0/0 ONLINE ONLINE node2
[root@node1 bin]# ./crs_unregister httpd_web
[root@node1 bin]# ./crs_unregister httpd_vip
[root@node1 bin]# ./crs_stat -t -v
Name Type R/RA F/FT Target State Host
----------------------------------------------------------------------
ora....SM1.asm application 0/5 0/0 ONLINE ONLINE node1
ora....E1.lsnr application 0/5 0/0 ONLINE ONLINE node1
ora.node1.gsd application 0/5 0/0 ONLINE ONLINE node1
ora.node1.ons application 0/3 0/0 ONLINE ONLINE node1
ora.node1.vip application 0/0 0/0 ONLINE ONLINE node1
ora....SM2.asm application 0/5 0/0 ONLINE ONLINE node2
ora....E2.lsnr application 0/5 0/0 ONLINE ONLINE node2
ora.node2.gsd application 0/5 0/0 ONLINE ONLINE node2
ora.node2.ons application 0/3 0/0 ONLINE ONLINE node2
ora.node2.vip application 0/0 0/0 ONLINE ONLINE node2
ora.racdb.db application 0/0 0/1 ONLINE ONLINE node2
ora....b1.inst application 0/5 0/0 ONLINE ONLINE node1
ora....b2.inst application 0/5 0/0 ONLINE ONLINE node2
[root@node1 bin]# ssh node2 /u01/app/crs_home/bin/crs_stat -t -v
root@node2's password:
Name Type R/RA F/FT Target State Host
----------------------------------------------------------------------
ora....SM1.asm application 0/5 0/0 ONLINE ONLINE node1
ora....E1.lsnr application 0/5 0/0 ONLINE ONLINE node1
ora.node1.gsd application 0/5 0/0 ONLINE ONLINE node1
ora.node1.ons application 0/3 0/0 ONLINE ONLINE node1
ora.node1.vip application 0/0 0/0 ONLINE ONLINE node1
ora....SM2.asm application 0/5 0/0 ONLINE ONLINE node2
ora....E2.lsnr application 0/5 0/0 ONLINE ONLINE node2
ora.node2.gsd application 0/5 0/0 ONLINE ONLINE node2
ora.node2.ons application 0/3 0/0 ONLINE ONLINE node2
ora.node2.vip application 0/0 0/0 ONLINE ONLINE node2
ora.racdb.db application 0/0 0/1 ONLINE ONLINE node2
ora....b1.inst application 0/5 0/0 ONLINE ONLINE node1
ora....b2.inst application 0/5 0/0 ONLINE ONLINE node2
[root@node1 bin]# ./corconfig -import a.ocr
-bash: ./corconfig: No such file or directory
<strong>[root@node1 bin]# ./ocrconfig -import a.ocr
PROT-19: Cannot proceed while clusterware is running. Shutdown clusterware first（<span>在导入ocr是集群必须要关闭</span>）</strong>
[root@node1 bin]# ./crsctl stop crs
Stopping resources. This could take several minutes.
Successfully stopped CRS resources.
Stopping CSSD.
Shutting down CSS daemon.
Shutdown request successfully issued.
[root@node1 bin]# ssh node2 /u01/app/crs_home/bin/crsctl stop crs
root@node2's password:
Stopping resources. This could take several minutes.
Successfully stopped CRS resources.
Stopping CSSD.
Shutting down CSS daemon.
Shutdown request successfully issued.
[root@node1 bin]# ./ocrconfig -import a.ocr
[root@node1 bin]# ./crsctl start crs
Attempting to start CRS stack
The CRS stack will be started shortly
[root@node1 bin]# ssh node2 /u01/app/crs_home/bin/crsctl start crs
root@node2's password:
Attempting to start CRS stack
The CRS stack will be started shortly
[root@node1 bin]# ./crs_stat -t -v
Name Type R/RA F/FT Target State Host
----------------------------------------------------------------------
httpd_vip application 0/1 0/0 ONLINE ONLINE node1
httpd_web application 1/1 0/4 ONLINE ONLINE node1
ora....SM1.asm application 0/5 0/0 ONLINE OFFLINE
ora....E1.lsnr application 0/5 0/0 ONLINE ONLINE node1
ora.node1.gsd application 0/5 0/0 ONLINE ONLINE node1
ora.node1.ons application 0/3 0/0 ONLINE ONLINE node1
ora.node1.vip application 0/0 0/0 ONLINE ONLINE node1
ora....SM2.asm application 0/5 0/0 ONLINE ONLINE node2
ora....E2.lsnr application 0/5 0/0 ONLINE ONLINE node2
ora.node2.gsd application 0/5 0/0 ONLINE ONLINE node2
ora.node2.ons application 0/3 0/0 ONLINE ONLINE node2
ora.node2.vip application 0/0 0/0 ONLINE ONLINE node2
ora.racdb.db application 0/0 0/1 ONLINE OFFLINE
ora....b1.inst application 0/5 0/0 ONLINE OFFLINE
ora....b2.inst application 0/5 0/0 ONLINE OFFLINE
下面是由restore来恢复ocr
[root@node1 crs]# ll -h /u01/app/crs_home/bin/a.ocr
-rw-r--r-- 1 root root 93K Aug 1 16:06 /u01/app/crs_home/bin/a.ocr
[root@node1 crs]# ll -h
total 25M
-rw-r--r-- 1 root root 4.4M Jul 31 12:36 35521234
-rw-r--r-- 1 oracle root 3.5M Jul 22 14:04 backup00.ocr
-rw-r--r-- 1 oracle root 3.5M Jul 10 14:04 backup01.ocr
-rw-r--r-- 1 oracle root 3.5M Jul 9 14:00 backup02.ocr
-rw-r--r-- 1 oracle root 3.5M Jul 22 14:04 day.ocr
-rw-r--r-- 1 oracle root 85K Jul 24 15:27 ocr.exp
-rw-r--r-- 1 oracle root 3.5M Jul 10 14:04 week_.ocr
-rw-r--r-- 1 oracle root 3.5M Jul 3 14:15 week.ocr
[root@node1 crs]# ocrconfig -restore /u01/app/crs_home/bin/a.ocr
PROT-22: Storage too small
[root@node1 crs]# ocrconfig -restore /u01/app/crs_home/cdata/crs/backup00.ocr
PROT-19: Cannot proceed while clusterware is running. Shutdown clusterware first
说明：export导出的文件只能是由import导入，restore时，cluster也必须全部离线
具体的操作过程这里不再演示，