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

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

Failure Groups Controller 1 Controller 2 Controller 3 Failure group 1 6 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

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

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

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

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

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

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

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

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

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