Create DR Database for Oracle

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Introduction

Dbvisit Standby Multiplatform can assist in creating the standby database.  Dbvisit Standby Multiplatform supports the creation of standby databases even if ASM or OMF are used.  If you are still using RAW devices, Dbvisit Standby Multiplatform can also support this.

Dbvisit Standby Multiplatform also supports the creation of an Oracle RAC enabled standby database. Since Oracle is discontinuing RAC for Standard edition from 19c, Dbvisit standby also support HA Clusterware for Oracle Standard Edition. There are a number of prerequisites before this can be performed. For example, the standby environment must already have the Clusterware (GI) installed and ASM storage configured, as well as have the Oracle Database software installed, this option will be discussed in more detail in this section.

Before getting into the more advanced configurations it is important to first make sure you understand the basics and then move on to the more advanced configurations.  

Dbvisit Standby Multiplatform will guide you through the creation of the standby process, and by answering a few short questions you will be ready to start the process.

Creating a standby database can be done in two ways:

  • Creating the standby database manually  (this option will not be discussed in this guide - for more detail please see the Oracle Documentation)

  • Creating the standby database using the Central Console - GUI

Please note that this guide will refer to the Create Standby Database process as the CSD process.

When creating a Standby database ensure that the sector size of standby server storage (ASM or filesystem) is the same as on the primary side. If you're not sure, contact Dbvisit Support

If using ASM based databases, we do not recommend the use of ASM aliases but rather use Oracle Managed File naming.

If you do create a standby database where ASM is used and the primary database is making use of ASM aliases, the standby database will only end up with OMF datafiles and ASM aliases will not be created.  

ASM Aliases can be created post CSD either using a post-processing script or by manually creating them.

As a prerequisite, you have to make sure that the Primary database uses SPFILE and not PFILE before running the Create Standby Database process.

If you are using ODA machines, It is required that you create the dbstorages before creating the standby databases using Dbvisit. Please refer to v10 documentation for the example of creating dbstorage:

https://support.dbvisit.com/hc/en-us/articles/360002847095-Configuring-Oracle-Database-Appliance-and-Dbvisit-Standby-v10

2.  Creating the Standby Database - Control Center (GUI)

In the following example we will create a standby database based on the following information:

  • Primary Server Details:

    • Server Name: dbvel71

    • DB_NAME: orcl21c

    • DB_UNIQUE_NAME: orcl21c

    • The database is in archivelog mode

    • Database archive log destination is set to the default recovery area (FRA) - /u01/oracle/fast_recovery_area

    • There is a local backup folder /home/oracle/temp which has sufficient space to hold a full compressed backup of the primary orcl21c database (RMAN Backup)

    • The database data files are located in /u01/oracle/oradata/ORCL21C

    • NON-OMF is used 

  • Standby Server Details:

    • Server Name: dbvel72

    • The DB_NAME and DB_UNIQUE_NAME will be the same as the primary

    • The same folder structure as the primary will be used 

    • The Oracle Database software is already installed on the standby server and match the same version and edition of the primary

    • The standby server also has a /home/oracle/temp folder with sufficient space for a full RMAN database backup

In this example, the ideal configuration is used. This means that the primary and standby database servers are an exact match with regards to storage and the directory structure.

In this case, it will not be required to set any additional parameters such as the db_file_name_convert or log_file_name_convert parameters.

The Setting up DR database can be initiated in two ways. As explained in the below diagram, by clicking on Set up Disaster Recovery now ( 1 ) or Set up Disaster Recovery ( 2 ).

This would result in loading the configuration and running pre-checks to see if the standby server is ready for the operations to be performed.

2.1 Creating Single Instance Standby

Below are the options that need to consider before creating the standby database.

( 1 ) Parallel option: By default, this option is marked as yes. This would enable you to backup the database, transfer the backup to standby and start restoring the transferred files in parallel. All these operations would be done in parallel.

( 2 ) Transportable Media: Set this to Yes, if you want to use physical external media (External hard disk or even NFS mounts) to manually move your database backup files. You may wish to do this if your database is very large and it would be faster to use a physical drive to move the data from source to destination locations. Enabling this option would automatically disable the parallel option mentioned in ( 1 ).

NOTE: Choosing to use Transportable Media will effectively split the CSD process into two distinct parts: Backup and Restore. Once all necessary data is Backed up onto your Transportable Media, you will need to physically move it to the Destination Host and continue the process into the Restore stage.

( 3 ) Source and Target Temp locations: These locations must have enough free space in the disk to accommodate full backup of the primary database. The default backup is taken as compressed RMAN backup sets.

( 4 ) Manage Oracle Parameters: Expanding this would give the list of oracle init parameters that can be changed to meet the requirements of your standby database.

( 5 ) Automated Standby Update: This by default is set to Yes and the interval is set to 10mins. Enabling this would automatically send archive logs from primary and apply them on standby. This is similar to the daemon services which we enable in previous versions of Dbvisit standby. It is recommended to keep it at least to 10mins and not below. This can however be increased based on requirements. If no archive logs are generated in primary it would wait for 10mins and do a log switch and transfer the archive log from primary to standby and apply the archive log on standby.

( 6 ) Observer: This by default is set to Yes. The main function of the observer is to monitor your configuration and report any issues detected in the dashboard. The various options of an Observer are covered separately in the later section.

( 7 ) Create Standby Database: Once all the above options are properly set, clicking this button would initiate the standby database creation.

( 8 ) Save as Template: This will create a template with the saved parameters. The standby database creation process is not initiated, but you could start the Setup Disaster Recovery and use the template to proceed with standby database creation.

2.2 Standby Creation Tasks

The task progress can be viewed on the Tasks & Events Bar on the right ( 1 ). When the task is clicked, the entire progress of the task is viewed ( 2 )along with steps that have been completed and also steps currently running, and future steps.

The below screenshot confirms that all the tasks related to standby database creation are completed and the standby database has been successfully created. This also confirms that the automatic standby update settings for sending and applying archive logs with a time gap of 10mins have been successfully enabled. The observer settings have also been enabled.

2.3 Standby Dashboard

The below screenshot clearly shows the standby’s time lag from Primary ( 1 ). The status of the primary database ( 2 ) and the status of the standby database ( 3 )

2.4 Additional options Under Database configurations

2.4.1 DR Readiness Score

This is a new feature from multiplatform. For every important functionality enabled and used a score is given. The maximum attainable score would be 10. The below configuration has a score of 8 out of 10 as we have not enabled notification and we have not configured standby update delay.

From the database configuration, it can also be seen the options that are enabled and the ones that are not enabled. From the below screenshot it can be noted that Automatic Standby Update ( 1 ) and

Observer ( 3 ) is enabled. But, Standby update delay ( 2 ) and Email notifications are disabled ( 4 ). This is an easier way to keep track of functions and features that are enabled for a particular configuration, unlike previous versions in which we have to check the Dbvisit Database Configuration file to check these.

3. Create Standby Database using ASM storage

The standby database creation does not change much when using ASM storage. Grid installation for ASM by default comes with Oracle Restart and with this, there is an option to use srvctl for registering the database and use it for stopping/starting the database using the Control center. This is an optional setting and can be set to Yes or No based on user preference. Dbvisit recommends this setting to be set to Yes

The Manage Oracle Parameters ( 1 ) option is expanded, the spfile configuration of the primary database is listed but this would be used as such in the standby if there is no difference in locations and directories file structure between primary and standby. The parameters db_create_file_dest ( 3 ) and the db_recovery_file_dest ( 4 ) should point to the correct locations on the standby server. Any database parameter changes can be done by clicking on Add Parameter ( 2 ) and the desired parameters can be added to the standby database.

If the Primary database server is using ASM OMF datafile and the standby is using a file system ( This is a supported configuration). Then the db_create_file_dest ( 3 ) and db_recovery_file_dest ( 4 ) location must point to filesystem location in standby.

If the Primary database has a mix of OMF and non-OMF data files then ensure that the below parameters are properly configured before create the standby database in the Manage Oracle Parameters section.

db_create_file_dest

db_recovery_file_dest

db_file_name_convert

log_file_name_convert

db_create_online_log_dest_n

4. Create Standby Database on Oracle Database Appliance (ODA) KVM

When creating the standby database in ODA KVM environment you need to manually change the following parameters:

  1. Click Manage Oracle Parameters

  2. Locate log_archive_dest_1 and log_archive_dest_10 parameters

  3. Escape the comma character in both parameters, i.e. set the following:

    1. log_archive_dest_1 to LOCATION=USE_DB_RECOVERY_FILE_DEST VALID_FOR=(ALL_LOGFILES\,ALL_ROLES) MAX_FAILURE=1 REOPEN=5 DB_UNIQUE_NAME=TEST03 ALTERNATE=log_archive_dest_10

    2. log_archive_dest_10 to LOCATION=+DATA/TEST03/arc10 VALID_FOR=(ALL_LOGFILES\,ALL_ROLES) DB_UNIQUE_NAME=TEST03 ALTERNATE=log_archive_dest_1

  4. Locate use_large_pages parameter

  5. Change the parameter value to FALSE (see also the following KB article for more details https://support.dbvisit.com/hc/en-us/articles/4973573379727-CSD-failed-with-ORA-27125)

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