在11g 安装过程中默认只能指定一个 dg 用来存储：crs ，voting
但是oracle 官方一般建议我们这么来配置：
1、当ocr没有配置镜像，或者冗余存储时 最少3个ocr 。
如果底层存储不是RAID的话，oracle建议镜像OCR，镜像可以避免单点故障。
■ At least two OCR locations if OCR is configured on an Oracle ASM disk group.
You should configure OCR in two independent disk groups. Typically this is the
work area and the recovery area.
2、如果ocr 配置在oracle asm disk group上时，建议最少两个ocr 位置
ocr 应当配置在两个单独的 disk group
■ At least two OCR locations if OCR is configured on mirrored hardware or
third-party mirrored volumes.
3、如果ocr 配置在有镜像的硬件或者在第3方的镜像卷上时也建议最少冗余2个ocr
eg：添加多个ocr （最多5个）
ocrconfig -add +asm_disk_group| file_name
ocrconfig -delete +ASM_disk_group| file_name
[root@vmrac1 ~]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 ~]# ocrconfig -add +ARCH --------------------------添加一个新的ocr +ARCH
[root@vmrac1 ~]# ocrcheck ------------------------------检查后已经成功添加
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +ARCH
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
同理再添加几个 dg
[root@vmrac1 ~]# ocrconfig -add +DATANEW
[root@vmrac1 ~]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +ARCH
Device/File integrity check succeeded
Device/File Name : +DATANEW
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 ~]# ocrconfig -add +FLASH
[root@vmrac1 ~]# orcheck
-bash: orcheck: command not found
[root@vmrac1 ~]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +ARCH
Device/File integrity check succeeded
Device/File Name : +DATANEW
Device/File integrity check succeeded
Device/File Name : +FLASH
Device/File integrity check succeeded
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 ~]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +ARCH
Device/File integrity check succeeded
Device/File Name : +DATANEW
Device/File integrity check succeeded
Device/File Name : +FLASH
Device/File integrity check succeeded
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 ~]# ocrcheck -local
Status of Oracle Local Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 2728
Available space (kbytes) : 259392
ID : 935756415
Device/File Name : /u02/app/11.2.0.3/grid/cdata/vmrac1.olr
Device/File integrity check succeeded
Local registry integrity check succeeded
Logical corruption check succeeded
------------这里我们再来看下ocr 的配置信息 ，配置文件在Linux环境下位于 /etc/oracle/ocr.loc
[root@vmrac1 ~]# cd /etc/oracle
[root@vmrac1 oracle]# ls
lastgasp ocr.loc ocr.loc.orig olr.loc olr.loc.bkp olr.loc.orig oprocd scls_scr setasmgid
[root@vmrac1 oracle]# more ocr.loc
#Device/file getting replaced by device +FLASH
ocrconfig_loc=+CRS
ocrmirrorconfig_loc=+ARCH ----------新添加的 ocr 镜像组
ocrconfig_loc3=+DATANEW
ocrconfig_loc4=+FLASH
local_only=false
[root@vmrac1 oracle]# more olr.loc
olrconfig_loc=/u02/app/11.2.0.3/grid/cdata/vmrac1.olr
crs_home=/u02/app/11.2.0.3/grid
-----------这里处理添加新的ocr外，我们也可以替换老的 ocr dg：
[root@vmrac1 oracle]# ocrconfig -replace +ARCH -replacement +FLASH
[root@vmrac1 oracle]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +FLASH
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 oracle]# ocrconfig -replace +FLASH -replacement +ARCH
[root@vmrac1 oracle]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File Name : +ARCH
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 oracle]#
---------------------注意：当 只有一个 ocr dg 时以上命令会报错：
[root@vmrac1 oracle]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3540
Available space (kbytes) : 258580
ID : 1902812549
Device/File Name : +CRS
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@vmrac1 oracle]# ocrconfig -replace +CRS -replacement +ARCH
PROT-28: Cannot delete or replace the only configured Oracle Cluster Registry location
[root@vmrac1 oracle]#
正确做法：
如果当前的ocr 少于2个 ，则上述ocr 的替换命令会出错
如果只有一个ocr 时我们可以先添加一个ocr ，再删除原来的ocr
# ocrconfig -add new_OCR_location
# ocrconfig -delete current_OCR_location
oracle 11g ocr 冗余配置,布布扣,bubuko.com
原文：http://blog.csdn.net/lixora/article/details/30506343