1. ASM General Architecture
Node1
Node2
Group Services tom=ant
dick=ant harry=ant
Group Services tom=bee
dick=bee harry=bee
DB Instance
SID=sales
DB Instance
SID=sales
DBW0
ASMB
ASMB
DBW0
ASM Instance
SID=ant
ASM Instance
SID=bee
RBAL FG FG
RBAL FG FG
ASMB
ASMB
RBAL
RBAL
DB Instance
SID=test
DB Instance
SID=test
DBW0
DBW0
ARB0
ARB0 … …
RBAL
RBAL
ARBA
ARBA
ASM Disks
ASM Disks
ASM Disks
ASM Disks
ASM Disks
ASM Disks
ASM Diskgroup Tom
ASM Diskgroup Dick
ASM Diskgroup Harry

2. Hierarchy Database ASM disk group Tablespace Data file ASM file
Segment
ASM disk
Extent
File system
file
or raw device
Allocation unit
Oracle block
Physical block

3. Failure Groups Controller 1 Controller 2 Controller 3 Failure group 16 5 4 3 2 1 7 13 1 7 13 1 7 13 1 7 13 1 7 13 1 7 13 1 7 13 1 7 13 1 7 13
Failure group 1
Failure group 2
Failure group 3
Disk group A

4. ASM file automatically spread inside disk group dgroupA
ASM Files
CREATE TABLESPACE sample DATAFILE '+dgroupA';
Database File 1
Automatic ASM file creation 2 3 4 1 2 3 4
ASM file automatically spread inside disk group dgroupA

5. RAC Software Storage Principles
Node1
Noden
Node1
Noden
Instance1 …
Instancen
Instance1 …
Instancen
CRS home
CRS home * *
Oracle home
Oracle home
Local storage
Local storage
Local storage
Local storage
Voting file
Voting file
OCR file
OCR file
Shared storage
CRS home
Oracle home
Shared storage
Oracle Real Application Clusters Installation and Configuration guide.
Permits online patch upgrades
Software not a single point of failure

6. OCR Architecture Node1 Node2 Node3 OCR Cache OCR Cache OCR Cache
OCR process
OCR process
OCR process
Client process
Client process
Shared storage
OCR file

7. RAC Database Storage Principles
Node1
Noden …
Instance1
Instancen
Archived log files
Archived log files
Local storage
Local storage
Online redo log files for instance1
Online redo log files for instancen
Data files
Undo tablespace files for instance1
Undo tablespace files for instancen
Flash recovery area files
Change tracking file
SPFILE
Control files
Temp files
Shared storage

8. Typical Cluster Stack with RAC
Servers
Interconnect
High-speed Interconnect
Proprietary
uDAPL or UDP
Proprietary
Oracle CRS
OS C/W
RAC
Linux, UNIX,
Windows
RAC
Linux
Windows
RAC
Linux
Windows
RAC
AIX, HP-UX, Solaris
ASM
OCFS
RAW
ASM
RAW
CFS
OS CVM
Database shared storage

9. RAC and Services Application server ERP CRM Listeners
Run time load balancing
Service location transparency
Service connections
Listeners
Connection load balancing
Service availability aware
Stop/Start service connections
RAC Instances
ERP
ERP
ERP
ERP
Backup
Modify service to instance mapping
Priority
CRM
CRM
Alerts
CRM
CRM
Tuning
CRS
Up and down events notification engine
Restart failed components

10. Virtual IP Addresses and RAC
clnode-1
clnode-2
clnode-1vip
clnode-2vip 2
Clients 2
ERP=(DESCRIPTION= ((HOST=clusnode-1))
((HOST=clusnode-2))
(SERVICE_NAME=ERP))
ERP=(DESCRIPTION= ((HOST=clusnode-1vip))
((HOST=clusnode-2vip))
(SERVICE_NAME=ERP)) 4 1 5 1 6 6
Timeout wait 7 5 7 3 3
clnode-2vip
clnode-1
clnode-2 4
clnode-1vip

11. Managing OCR: Overview
The OCR content is critical to CRS.
The OCR is automatically backed up physically:
Every four hours: CRS keeps the last three
At the end of every day: CRS keeps the last two
At the end of every week: CRS keeps the last two
You can also:
Logically back up the OCR:
Copy physical OCR backups
Backups can be used for recovery purposes.
ocrconfig –showbackup
ocrconfig –backuploc
ocrconfig -export

12. Recovering the OCR 1. Locate either a physical or a logical backup.
2. Restart all the nodes in single-user mode.
3. Restore the physical OCR backup or import the logical OCR backup:
4. Restart all the nodes in multiuser mode.
$ ocrconfig –restore \
> /app/oracle/product/10.1.0/crs_1/cdata/jfv_clus/day.ocr
$ ocrconfig –import /u01/logical_ocr/yesterday