Before configuring disaster recovery (DR) services, check the database environments of the production end and the DR end where SAP HANA databases reside, and the storage end environment. If the database environments do not meet requirements, modify database configurations.
Production End and DR End
Check the database environments of the production end and the DR end where SAP HANA databases reside.
- When a database environment is configured at the production end where hosts running Suse12 or RedHat7 are deployed, the mount points of the file system used by the database cannot be nested. For example, mount points /testdb/ and /testdb/database1/ are nested.
- Before configuring a SAP HANA database, you must obtain the instance name, user name, and password of the SAP HANA database.
The instance name is the SAP HANA database instance name. The user name is that of the system user of the SAP HANA database instance. Usually, the user name is the same as the instance name. The password is that of the system user.
- Check whether the password of the SAP HANA database meets the requirements for input characters. If other special characters are entered, the database will fail to be authenticated during creating a protected group.
Supported characters: only letters, digits, and special characters including _#%^+-.,~@$.
Production End
- Check the database configuration at the production end.
eReplication of the current version supports DR for SAP HANA databases on Suse12 and RedHat7. To enable eReplication to perform DR for SAP HANA databases, the SAP HANA databases must meet the following requirements:
- Installation directories of SAP HANA instances must reside on local disks or independent storage devices and cannot reside on the same devices as databases for which DR is intended.
- Data files in the SAP HANA databases for which DR and protection are intended must be stored on LUNs provided by Huawei storage devices.
DR End
- Check the database environment at the DR end.
If the database environments at the DR end and production end are not the same, the user should deal with it to make sure that the DR end and production end have the same database environments.
Table 1 describes the lists configuration requirements.
Table 1 Configuration Requirement of the Database on the DR EndCheck Item
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Configuration Requirement
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Installation
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The operating system and its edition run by SAP HANA databases are the same as that at production end.
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The versions of SAP HANA databases are the same as that at the production end.
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Configuration
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The cluster where the SAP HANA databases reside at the DR end has the same configuration as that at the production end. The two clusters must have the same resource configuration and dependency among resources.
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Instance
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The instance names, numbers, user names, and passwords of databases are the same as that at the production end.
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The user groups to which users of SAP HANA database instances belong are the same as that at the production end.
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The installation directories of SAP HANA instances at the DR end reside on local disks or independent storage devices.
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The SAP HANA databases to be recovered are created under SAP HANA instances at the DR end and ensure that the created databases meet the following requirements:
- Names of databases are the same at the DR and production ends.
- Storage paths (file systems) used by databases are the same at the DR and production ends.
- Names of logical volumes used by databases and volume groups to which logical volumes belong are the same at the DR and production ends.
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- Close databases on the DR end.
After checking the database environments, close databases on the DR end before creating a recovery plan.
For a single SAP HANA device, close the database directly.
- Modify the configuration file of the database at the DR database end.
After shutting down the database at the DR end, modify the value of parameter id in the nameserver.ini configuration file of the database at the DR end to keep the value consistent with that of the database at the production end.
This value is used to identify storage devices of the database.
- Use PuTTY to log in to the server at the production end as user root.
- Run the following command to prevent PuTTY from exiting due to session timeout:
TMOUT=0
After you run this command, the system continues to run when no operation is performed, resulting a risk. For security purposes, you are advised to run the exit command to exit the system after completing your operations.
- Run the following command to view the value of id in the nameserver.ini configuration file. SID is the value of SAP HANA System ID set when you create a database. Set the value based on the site requirements.
cat /usr/sap/SID/SYS/global/hdb/custom/config/nameserver.ini
- Use PuTTY to log in to the server at the DR end as user root.
- Run the following command to prevent PuTTY from exiting due to session timeout:
TMOUT=0
After you run this command, the system continues to run when no operation is performed, resulting a risk. For security purposes, you are advised to run the exit command to exit the system after completing your operations.
- Run the following command to open the nameserver.ini configuration file: SID is the value of SAP HANA System ID set during creating a database. Set the value based on the site requirements.
vi /usr/sap/SID/SYS/global/hdb/custom/config/nameserver.ini
- Press i to enter the editing mode and find parameter id. Modify the value of id to be that obtained from Step 3.3.
- Press ESC to enter the browsing mode, and then press Shift and : simultaneously. Run wq! to save and exit.
- Replace the database SSFS verification files used at the DR end with those used at the production end.
/hana/shared/SID/global/hdb/security/ssfs/SSFS_SID.DAT
/hana/shared/SID/global/hdb/security/ssfs/SSFS_SID.KEY
SID indicates the value of SAP HANA System ID specified during the database creation.
Storage End
Check the storage environments of the production end.
- Map the initiator of the physical DR host to the logical host of the DR storage. In a cluster, add the logical host to the host group.
- If the storage is T series V2R2 or later or 18000 series, the storage support automatically add host and storage mapping function. If the connection between the storage device and the host initiator is normal, the hosts, host groups, LUN mappings, and mapping view will be created in the storage device automatically.
- If the storage array is T series V200R001C00, deselect Enable Inband Command to change the mapping view attribute after the mapping view is created.
- If the storage array is FusionStorage V100R006C30SPC100, mount a linked clone volume of a Huawei Distributed Block Storage snapshot to another Huawei Distributed Block Storage storage device. The two storage devices must use the same block storage client.
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