Recently one of our consultant has upgraded grid and oracle database on Oracle Exadata from 11.2.0.3 to 12.1.0.2. He has shared upgrade instructions as per the Oracle best practice and documentation.
Hope it will help who are planning to upgrade exadata environment.
If proper plan is in place than upgrade activity is not much difficult.
There are five main section for upgrade.
1. Prepare the Existing Environment
2. Install and Upgrade Grid Infrastructure to 12.1.0.2
3. Install Database 12.1.0.2 Software4. Upgrade Database to 12.1.0.2
5. Post-upgrade steps
Now let's see what all are the steps need to perform for each section.
1. Prepare the Existing Environment
Steps need to be performed in this sections are:
- Planning
- Review Database 12.1.0.2 Upgrade Prerequisites
- Download and distribution of the required Files
- Application of required patches
- Run Exachk
- Validate Readiness for Oracle Clusterware upgrade
- Execute and verify output of cluster verification utility and act if anything need to be done
2. Install and Upgrade Grid Infrastructure to 12.1.0.2
This will perform grid installation and upgrade it to 12.1.0.2. The Grid Infrastructure upgrade is performed in a RAC rolling fashion, this procedure does not require downtime.
Data Guard
If there is a standby database, then run these commands on the standby system separately to upgrade the standby system Grid Infrastructure. The standby Grid Infrastructure upgrade can be performed in parallel with the primary if desired.
However, the Grid Infrastructure home always needs to be on later or equal level than the Database home. Therefore upgrading Grid Infrastructure home needs to be done before a database upgrade can be performed.
Steps need to be performed in this sections are:
- Install MGMTDB or not
- Validate hugepage configuration for new ASM SGA requirements
- Create a snapshot based backup of the database server partitions
- Create the new GI_HOME directory where 12.1.0.2 will be installed
- Prepare installation software
- Perform 12.1.0.2 Grid Infrastructure software installation and upgrade using OUI
- Apply latest Bundle Patch contents to Grid Infrastructure Home using 'opatch napply' (when available)
- Change Custom Scripts and environment variables to Reference the 12.1.0.2 Grid Home
3. Install Database 12.1.0.2 Software
This section will install Oracle 12.1.0.2 RDBMS software in new Oracle Home. This section only installs Database 12.1.0.2 software into a new directory, this does not affect currently running databases, hence all the steps below can be done without downtime.
Data Guard
- If there is a separate system running a standby database and that system already has Grid Infrastructure upgraded to 12.1.0.2, then run these steps on the standby system separately to install the Database 12.1.0.2 software. The steps in this section can be performed in any of the following ways:
- Install Database 12.1.0.2 software on the primary system first then the standby system.
- Install Database 12.1.0.2 software on the standby system first then the primary system.
- Install Database 12.1.0.2 software on both the primary and standby systems simultaneously.
Steps need to be performed in this sections are:
- Prepare Installation Software
- Perform 12.1.0.2 Database Software Installation with OUI
- Update OPatch in the new Grid Infrastructure home and New Database Home on All Database Servers
- When available: Install Latest 12.1.0.2 Bundle Patch available for your operating system - Do Not Perform Post-Installation Steps
- When available: Apply 12.1.0.2 Bundle Patch Overlay Patches as Specified in Document 888828.1
- When available: Apply Customer-specific 12.1.0.2 One-Off Patches
4. Upgrade Database to 12.1.0.2
The commands in this section will perform the database upgrade to 12.1.0.2.
For Data Guard configurations, unless otherwise indicated, run these steps only on the primary database.
Steps need to be performed in this sections are:
- Backing up the database and creating a Guaranteed Restore Point
- Analyze the Database to Upgrade with the Pre-Upgrade Information Tool (if not done earlier)
- Data Guard only - Synchronize Standby and Switch to 12.1.0.2
- Data Guard only - Disable Fast-Start Failover and Data Guard Broker
- Before starting the Database Upgrade Assistant (DBUA) stop and disable all services with PRECONNECT as option for 'TAF Policy specification'
- Upgrade the Database with Database Upgrade Assistant
- Review and perform steps in Oracle Upgrade Guide, 'Post-Upgrade Tasks for Oracle Database'
- Change Custom Scripts and Environment variables to Reference the 12.1.0.2 Database Home
- Add Underscore Initialization Parameters back that were removed earlier
- When available: run 12.1.0.2 Bundle Patch Post-Installation Steps
- Data Guard only - Enable Fast-Start Failover and Data Guard Broker
- Delete Guaranteed Restore Point created before the upgrade
The database will be inaccessible to users and applications during the upgrade (DBUA) steps. Course estimate of actual application downtime is 30-90 minutes but required downtime may depend on factors such as the amount of PL/SQL that needs recompilation.
Note that it is not a requirement all databases are upgraded to the latest release. It is possible to have multiple releases of Oracle Database Homes running on the same system. The benefit of having multiple Oracle Homes is that multiple releases of different databases can run.
The disadvantage is that more planned maintenance is required in terms of patching. Older database releases may lapse out of the regular patching life cycle policy in time. Having multiple Oracle homes on the same node requires more disk space.
5. Post-upgrade Steps
Steps need to be performed in this sections are:
- Remove Guaranteed Restore Point if still exists
- DBFS only - Perform DBFS Required Updates
- Run Exachk and validate the exacheck report
- Verify nproc setting (CRS_LIMIT_NPROC) for Grid Infrastructure
- Deinstall the 11.2.0.2, 11.2.0.3, 11.2.0.4 or 12.1.0.1 Database and Grid Homes
- Re-configure RMAN Media Management Library
- Restore settings for concurrent statistics gathering
It is always better to read updated Oracle Doc ID to make smooth upgrade in timely manner.
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