SAP HANA

Before configuring DR services, check the SAP HANA database environment at the production and DR ends and the storage environment. If any environment does not meet requirements, modify its configurations.

Public Check Items

Check and configure the following items in the SAP HANA database environment at the production and DR ends.

When the host where the database resides run SUSE 11 or 12, or Red Hat 7, 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 an SAP HANA database, obtain the name and account (including username and password) of the database instance.
The instance name is the one you created, the username is the username of the system corresponding to the instance and usually is the same as the instance name.
Ensure that the password meets the complex requirements. Otherwise, databases may fail to be authenticated when you create a protected group. The password can only contain letters, digits, and the following special characters: _#%^+-.,~@$
Check whether the production host and DR host on which SAP HANA databases reside are consistent in name. If they are inconsistent, change them to be.

Check Items at the Production End

Check the database configuration at the production end.

eReplication of the latest version can protect SAP HANA databases in SUSE 11 and 12, and Red Hat 7 when the SAP HANA databases 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 and log files of the SAP HANA databases for which DR and protection are intended must be stored on LUNs provided by Huawei storage devices.
If the scheduling period of the protection policy is set to Second, data files and log files of SAP HANA databases must be stored on different LUNs provided by Huawei storage devices.

Check Items at the 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 DR database
Check Item	Configuration Requirement
Installation	The operating system type and version run by SAP HANA databases are the same as those at production end.
Installation	The SAP HANA database version is the same as that at the production end.
Configuration	The cluster where the SAP HANA databases reside at the DR end has the same configurations (including resources and dependencies among resources) as that at the production end.
Instance	The names, user names, and passwords of database instances are the same as those at the production end.
	The user groups to which users of SAP HANA database instances belong are the same as those at the production end.
	The installation directories of SAP HANA instances at the DR end reside on local disks or independent storage devices.
	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 or names of devices (raw devices) 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.

Close databases at the DR end.
- For a standalone SAP HANA database, close it directly.
- For an SAP HANA cluster, take the cluster resources or resource groups of the database offline.
Modify the database configuration file at the DR end.
After closing databases, manually modify the value of id in the nameserver.ini configuration file to be consistent with that at the production end.

This ID is used to identify the storage of the database.
1. Use PuTTY to log in to the production server as user root.
2. Run the following command to prevent PuTTY from logout due to timeout.
```
TMOUT=0
```
  After you run this command, the system continues to run when no operation is performed, resulting in a risk. For security purposes, you are advised to run exit to exit the system after completing your operations.
3. Run the following command to obtain the value of id in the nameserver.ini configuration file. SID indicates the value of SAP HANA System ID you set when configuring the database.
```
cat /usr/sap/SID/SYS/global/hdb/custom/config/nameserver.ini
```
4. Use PuTTY to log in the DR server as user root.
5. Run the following command to prevent PuTTY from logout due to timeout.
```
TMOUT=0
```
  After you run this command, the system continues to run when no operation is performed, resulting in a risk. For security purposes, you are advised to run exit to exit the system after completing your operations.
6. Run the following command to obtain the value of id in the nameserver.ini configuration file. SID indicates the value of SAP HANA System ID you set when configuring the database.
```
vi /usr/sap/SID/SYS/global/hdb/custom/config/nameserver.ini
```
7. Press i to go to the editing mode. Locate the value of id and replace it with the one you obtained in 3.c.
8. Press Ecs to go to the browsing mode. Press Shift and : at the same time and then run wq! to save the change and exit.
Replace the SSFS verification file of the DR database with that of the production database. The file paths are:
/hana/shared/SID/global/hdb/security/ssfs/SSFS_SID.DAT

/hana/shared/SID/global/hdb/security/ssfs/SSFS_SID.KE
- Replace SID with the value of SAP HANA System ID you set when configuring the corresponding database.
- The permission of the SSFS verification file of the database at the DR end must be the same as that of the SSFS verification file of the database at the production end.

Check Items at the Storage End

Perform the checks on storage at the production and DR ends.
If you use storage array remote replication to implement DR protection for the database, create a remote replication relationship between the production end and DR end on the storage array device management software page and ensure that the replication status is normal. The synchronous replication solution is not supported in the HyperVault DR scenario.

When the asynchronous replication solution is used, set up a remote replication relationship between the storage LUNs where the data file resides and set up a remote replication relationship between the storage LUNs where the log file resides.If multiple protected objects need to be added to a protected group, a remote replication relationship must be set up between the storage LUNs where the log files of each database instance reside or no remote replication relationship is set up.
Perform the checks on storage at the DR end.
1. Check that all file systems used by the SAP HANA database to be recovered are unmounted from the DR host.
2. After setting up an application environment at the DR site, delete the mapping between the host and the storage LUNs or volumes that store the data files and log files of the application.
  
  If the asynchronous replication solution is used and a remote replication relationship is not set up between the production end and the storage LUN where the data files reside at the DR end, the mapping between the host and the storage LUNs or volumes that store the data files and log files of the application does not need to be deleted.
3. If you use storage array remote replication to implement DR protection for the database, check that secondary LUNs corresponding to remote replication used by DR databases are not mapped to any host, host group, or mapping view on the storage array management software.
4. If the DR host runs the Linux operating system, check on the DR host whether the volume groups to which the logical volumes used by the database to be restored belong are deactivated and exported.