HANA Backup Configuration
SAP HANA Database Backup
Hana Backup Types
In this blog we have explained the HANA Backup Configuration , Hana Backup types, database recovery options, Estimate the Backup size, Backup parameter, data snapshot and FALLBACKUP Snapshot and Backup configuration details.
Hana Backup Types:
4 types of Hana backup is available
1. Full Backup
2. Differential Backup
3. Incremental Backup
4. Automatic Redo log Backup
Database Recovery:
1. Recovery most recent state
2. Specific point in time
3. Specific Data Backup
Using the below tools, we can take the Hana backup manually and schedule the Backup.
1. Hana cockpit
2. Hana studio
3. DBACOCKPIT
We can perform the DB restore activity using Hana cockpit and Hana studio.
Full Backup:
• Full Backup mean complete DB backup.
• At least Full Backup is required weekly basic.
Differential Backup:
• It is stored the all the data that changed since last complete data backup.
• The amount of the data to be saved with each differential backup increase.
Increase Full Backup:
• It is stored the all the data that changed since last complete data backup. Or the last delta backup(incremental or differential backup)
• If data remains unchanged it is not saved to more than one backup. For this reason incremental backups are the smallest of the backups.
How to Estimate the Size of the Backup:
• We can check the Backup size using Hana studio, hana cockpit & OS level using hdbsql.
• Command:
Select * from M_BACKUP_SIZE_ESTIMATIONS
Key points:
• Restore from higher version to lower Hana db version is not supported.
• Default hana data backup file location is $(DIR_instance)/backup/data
• If you want, you can change the Backup store location.
• 3rd party tools config us the destination /usr/sap/SID/SYS/global/hdb/ config
• Using SAP HANA Cockpit, only tenant database can be recovered to point in time.
• Recover the system database to point in time, use the recoverySys.py tool
Hana Backup Configuration:
Hana Backup configuration we will check below 3 parts.
• Data and log Backup destination path
• Log mode
• Backup retention period
Hana Backup Configuration through Hana Cockpit:
• Login Hana Cockpit
• Go to Database directory
• On the Database directory screen select the Database management
• Select the which system you will configure the Backup and create the Backup Wizard
• Use Backup schedule Wizard to configure the Backup to Backup strategy.
• Once Hana Backup configuration is completed then take the Backup(Log or data)
Log Backup:
• Based on system, we will configure the log backup interval.
• Log segment has saved in storage.
• All data changes are recorded in redo log buffer.
• When transaction is committed then redo log buffer is saved into log segment to Disk.
Log Backup parameter:
• You can enable or disable the automatic log backup using backup parameter.
Parameter:
Enable_auto_log_backup=yes
• If automatic log backup has enable then when log segment has full, log backup will triggered automatically.
• A time interval 0 means that log Backup are created only when log segment is full
• Need to maintained the below parameter for automatic log Backup.
Log_mode=normal
Enable_auto_log_backup=yes
Log_backup_timeout=0
• Log_mode=normal
If log_mode is normal then point in time recovery , full recovery & recovery to specific data backup has possible.
• Log_mode=overwrite
No point in time recovery is not possible because no log backups are triggered.
Global.ini file location in OS level:
• We can change the Hana Backup configuration files in Hana studio or Hana cockpit or OS level also. Please find the below path for configuration file location in OS level.
• Global configuration file path:
/usr/sap/SID/SYS/global/hdb/custom/config
• Tenant Database:
/usr/sap/SID/SYS/global/hdb/custom/config/db_tenate
How to check recovery is possible or not:
• Before recovery we need to check Backup is consistency or not using hdbbackupcheck
• Hdbrecovercheck.py and hdbbackupdiag can be used to check the Backup consistency before recovery.
• Python scripts : hdbrecovercheck.py
Data snapshot:
• Data snapshots offer to additional option for Back and recovery.
• Data snapshot capture the state of the data volume on storage system at particular time.
Re-initialize a non recoverable system database:
• The system DB is corrupted and can’t the be started any more but all tenant database has running fine.
• We don’t have the system db backup.
• In this situation only possible solution is re-initialize the SYSTEMDB instead od recovering the whole SAP HANA Database system including the all tenant databases.
• The command line tool hdbmdcutil all to reinitialize the system database with information on all tenant database of the sap hana instance.
• Command: hdbmdcutil –restoreTopology [–set_user_system_pw]
Please check the sap note for more information. SAP NOTE: 2588284
Creating FallBack snapshot:
• If you have performing the upgrade on application level.
• The fallbackup snapshot feature let you create the snapshot and easy to roll back quickly without complete Full Backup.
• Fallback snapshot are created on tenant database level win in few seconds
• SQL Command for create the snapshot
ALTER DATABASE tenant_nane CREATE FALLBACK SNAPSHOT;
• SQL Command for reset the FALL BACKUP
ALTER SYSTEM START DATABASE <Database name> FROM FALLBACK SNAPSHOT;
Conclusion:
we have explained the HANA Backup Configuration , Hana Backup types, database recovery options, Estimate the Backup size, Backup parameter, data snapshot and FALLBACKUP Snapshot and Backup configuration details.
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