Complete Guide for Cross-Platform Transportable Tablespaces (XTTS) with Incremental Backups: AIX to Linux Migration

 

Complete Guide for Cross-Platform Transportable Tablespaces (XTTS) with Incremental Backups: AIX to Linux Migration

This is a detailed, end-to-end guide for migrating an Oracle database from AIX to Linux using Cross-Platform Transportable Tablespaces (XTTS), with incremental backups to minimize downtime. The example will cover the migration of tablespaces (SALES and PRODUCTS) and ensure a smooth, low-downtime transition.

Prerequisites

• Oracle is installed on both source (AIX) and target (Linux) systems.
• Both systems have enough disk space for backups and the migration process.
• Network connectivity between source and target systems.
• ASM (if applicable) on both source and target systems.
• Oracle 11g/12c/19c (ensure compatibility with XTTS).

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Step 1: Download and Unzip the XTTS Utility

1. Download rman_xttconvert_VER4.3.zip from Oracle Support or use the package provided by Oracle.
2. On the Source (AIX) system, unzip the rman_xttconvert_VER4.3.zip package:

   
   unzip rman_xttconvert_VER4.3.zip -d /home/oracle/xtts
   

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Step 2: Set Up Working Directories for Backup Files

1. Create the same directory on both source and target systems for storing backups and migration data:

   
   mkdir -p /home/oracle/xtts
   

2. Ensure enough space for backups on both systems. You can check disk space using df -h.

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Step 3: Configure xtt.properties File

The xtt.properties file contains the configuration details for the migration.

1. Create the xtt.properties file on the source system (/home/oracle/xtts/xtt.properties):

   properties
   
   SOURCE_SID=ORCL_AIX
   TARGET_SID=ORCL_LINUX
   PLATFORM_NAME=AIX-Based Systems
   TARGET_PLATFORM_NAME=Linux x86 64-bit
   BACKUP_LOCATION=/home/oracle/xtts/backups
   TRANSFER_DIR=/home/oracle/xtts/transfer
   TABLESPACES=SALES,PRODUCTS
   TARGET_DATAFILE_LOCATION=/u01/app/oracle/oradata/ORCL_LINUX
   TARGET_PLATFORM_ID=13
   PARALLEL=4
   ASM_HOME=/u01/app/grid
   ASM_SID=+ASM
   

   Key fields:

   • TABLESPACES=SALES,PRODUCTS: Specifies the tablespaces to migrate.
   • TARGET_PLATFORM_ID=13: Specifies the Linux platform ID (use SELECT * FROM v$transportable_platform; to find this for your platform).
   • ASM_HOME and ASM_SID: Only needed if using ASM.

2. Transfer the configuration file to the target system:

   
   scp /home/oracle/xtts/xtt.properties oracle@<target_ip>:/home/oracle/xtts/
   

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Step 4: Backup the Source Database

On the source system (AIX), take a full RMAN backup for the SALES and PRODUCTS tablespaces:

1. Log in as Oracle user and set the environment:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   

2. Run the RMAN backup command using xttdriver.pl:

   
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --backup
   

• This will create the backup files in /home/oracle/xtts/backups.
• If your backup uses ASM, ensure the appropriate paths for ASM are set in xtt.properties.

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Step 5: Move Backup to Target System

1. Transfer the RMAN backup to the target system (Linux):

   
   scp /home/oracle/xtts/backups/* oracle@<target_ip>:/home/oracle/xtts/backups/
   

2. Transfer the res.txt file for tracking:

   
   scp /home/oracle/xtts/res.txt oracle@<target_ip>:/home/oracle/xtts/
   

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Step 6: Restore the RMAN Backup on the Target System

1. Log in to the target (Linux) system as Oracle user.

2. Set TMPDIR for restoration:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   

3. Run the restore command to restore the backup:

   
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --restore
   

   This command restores the backup files and converts them to the appropriate endian format if necessary.

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Step 7: Perform Incremental Backups

Incremental backups minimize the lag between the source and target systems, reducing downtime.

1. Take incremental backups on the source system:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --backup
   

2. Transfer the incremental backups and res.txt file to the target system:

   
   scp /home/oracle/xtts/backups/* oracle@<target_ip>:/home/oracle/xtts/backups/
   scp /home/oracle/xtts/res.txt oracle@<target_ip>:/home/oracle/xtts/
   

3. Restore the incremental backups on the target system:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --restore
   

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Step 8: Prepare for Downtime

When the downtime window starts, follow these steps to minimize the downtime:

1. Gather dictionary stats for faster Data Pump export:

   
   EXEC DBMS_STATS.GATHER_DICTIONARY_STATS;
   

2. Set tablespaces to read-only to prevent further changes:

   
   ALTER TABLESPACE SALES READ ONLY;
   ALTER TABLESPACE PRODUCTS READ ONLY;
   

3. Perform the final incremental backup:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --backup
   

4. Transfer the final incremental backup to the target system:

   
   scp /home/oracle/xtts/backups/* oracle@<target_ip>:/home/oracle/xtts/backups/
   

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Step 9: Final Restore on the Target System

1. Log in to the target system and set TMPDIR:

   
   export TMPDIR=/home/oracle/xtts
   cd /home/oracle/xtts
   

2. Restore the final incremental backup:

   
   $ORACLE_HOME/perl/bin/perl xttdriver.pl --restore
   

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Step 10: Final Steps to Complete Migration

1. Open the tablespaces on the target system:

   
   ALTER TABLESPACE SALES READ WRITE;
   ALTER TABLESPACE PRODUCTS READ WRITE;
   

2. Verify the target system to ensure data integrity:

   
   SELECT tablespace_name, status FROM dba_tablespaces;
   

3. Test the application connected to the target database for functionality and performance.

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Step 11: Clean Up

1. Remove the read-only mode for the USERS tablespace on the source:

   
   ALTER TABLESPACE USERS READ WRITE;
   

2. Clean up temporary directories from both source and target systems if needed.

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Important Considerations

• Backup Size: Ensure that there is enough space to store the backups and restored data on both source and target systems.
• Endianness Conversion: If migrating from a platform with a different endian format (e.g., AIX to Linux), XTTS handles the conversion of data files automatically.
• Incremental Backups: Run incremental backups as often as possible before the final downtime to minimize lag and reduce downtime.
• ASM: If using ASM on either system, make sure the proper ASM paths are set in xtt.properties.

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By following this detailed guide, you'll be able to perform a Cross-Platform Transportable Tablespace (XTTS) migration with minimal downtime, ensuring a smooth transition of the SALES and PRODUCTS tablespaces from AIX to Linux.