In large production environments, RMAN backup performance is heavily dependent on proper channel configuration and parallelism tuning. This case study demonstrates a real-world scenario where RMAN SBT_TAPE parallelism was increased and channel configuration was modified to improve backup performance.
This example is from a production system using SBT_TAPE integration with external backup software.
Initial RMAN Configuration
Below is the existing RMAN configuration before making any changes:
RMAN> SHOW ALL;
RMAN configuration parameters for database with db_unique_name pbiRA are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE SBT_TAPE TO '%F'; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 4 BACKUP TYPE TO BACKUPSET;
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS
'SBT_LIBRARY=/u02/app/oracle/product/19.0.0/dbhome_1/lib/libra.so,
ENV=(RA_WALLET=location=file:/u02/app/oracle/product/19.0.0/dbhome_1/wallet_pbitest_vip2
CREDENTIAL_ALIAS=pbidcrpl-vip.pbi.com:1522/pbifincr:dedicated)';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE; # default
CONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO
'/u02/app/oracle/product/19.0.0/dbhome_1/dbs/snapcf_pbiTEST.f'; # default
The system was configured with parallelism set to 4, which was not sufficient for high-throughput backup requirements.
Change 1: Increase SBT_TAPE Parallelism
To improve backup performance, parallelism was increased from 4 to 12.
RMAN> CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 12 BACKUP TYPE TO BACKUPSET;
old RMAN configuration parameters:
CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 4 BACKUP TYPE TO BACKUPSET;
new RMAN configuration parameters:
CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 12 BACKUP TYPE TO BACKUPSET;
new RMAN configuration parameters are successfully stored
Increasing parallelism allows RMAN to allocate more channels, enabling faster data transfer to tape or backup media.
Change 2: Update Channel Configuration
The channel configuration was updated to use a new wallet location and SCAN-based connection.
RMAN> CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS
'SBT_LIBRARY=/u02/app/oracle/product/19.0.0/dbhome_1/lib/libra.so,
ENV=(RA_WALLET=location=file:/u02/app/oracle/product/19.0.0/dbhome_1/ra_wallet
CREDENTIAL_ALIAS=pbidcrpl-scan1.pbi.com:1522/pbifincr:dedicated)';
old RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS
'SBT_LIBRARY=/u02/app/oracle/product/19.0.0/dbhome_1/lib/libra.so,
ENV=(RA_WALLET=location=file:/u02/app/oracle/product/19.0.0/dbhome_1/wallet_pbitest_vip2
CREDENTIAL_ALIAS=pbidcrpl-vip.pbi.com:1522/pbifincr:dedicated)';
new RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS
'SBT_LIBRARY=/u02/app/oracle/product/19.0.0/dbhome_1/lib/libra.so,
ENV=(RA_WALLET=location=file:/u02/app/oracle/product/19.0.0/dbhome_1/ra_wallet
CREDENTIAL_ALIAS=pbidcrpl-scan1.pbi.com:1522/pbifincr:dedicated)';
new RMAN configuration parameters are successfully stored
Switching to SCAN connection improves load balancing and high availability in RAC environments.
Final RMAN Configuration
After applying changes, the configuration was verified:
RMAN> SHOW ALL;
RMAN configuration parameters for database with db_unique_name pbiRA are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE SBT_TAPE TO '%F'; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 12 BACKUP TYPE TO BACKUPSET;
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS
'SBT_LIBRARY=/u02/app/oracle/product/19.0.0/dbhome_1/lib/libra.so,
ENV=(RA_WALLET=location=file:/u02/app/oracle/product/19.0.0/dbhome_1/ra_wallet
CREDENTIAL_ALIAS=pbidcrpl-scan1.pbi.com:1522/pbifincr:dedicated)';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE; # default
CONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO
'/u02/app/oracle/product/19.0.0/dbhome_1/dbs/snapcf_pbiTEST.f'; # default
Key Observations
- Parallelism increased from 4 to 12
- Channel configuration updated to new wallet location
- SCAN-based connection used instead of VIP
Performance Impact
After increasing parallelism:
- Backup throughput improved significantly
- Better utilization of available channels
- Reduced backup window
Best Practices
- Align RMAN parallelism with CPU, I/O, and media manager capacity
- Avoid over-allocation of channels to prevent resource contention
- Use SCAN for RAC environments
- Validate backup performance after changes
Key Takeaways
RMAN parallelism directly impacts backup performance.
Proper channel configuration is critical for SBT_TAPE backups.
SCAN-based configuration improves RAC stability.
Always validate changes in production environments.
Conclusion
Tuning RMAN configuration is essential for achieving optimal backup performance in large databases. This real-world example highlights how increasing parallelism and updating channel configuration can significantly improve backup efficiency.
Toufique Khan
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