SAP HANA Setup and HSR

Prepare SAP HANA for System Replication (HSR) by configuring parameters and creating required backups.

Review AWS and SAP Installation Guides

SAP provides documentation on how to configure SAP HANA System Replication using the SAP HANA Cockpit, SAP HANA Studio or hdbnsutil on the command line. Review the documentation for your SAP HANA Version to ensure no changes to the guidance or to use a method other than command line.

Check global.ini parameters

Run the following as <sid>adm. These commands will prompt for the system password for the SYSTEMDB database.

Check log_mode is set to normal

Ensure that the configuration parameter log_mode is set to normal in the persistence section of the global.ini file:

hdbsql -jx -i <hana_sys_nr> -u system -d SYSTEMDB "SELECT VALUE FROM M_INIFILE_CONTENTS WHERE FILE_NAME = 'global.ini' AND SECTION = 'persistence' AND KEY = 'log_mode';"

For example:

hdbadm> hdbsql -jx -i 00 -u system -d SYSTEMDB "SELECT VALUE FROM M_INIFILE_CONTENTS WHERE FILE_NAME = 'global.ini' AND SECTION = 'persistence' AND KEY = 'log_mode';"
VALUE
"normal"

Review global.ini file replication

SAP HANA System Replication requires consistent configuration between primary and secondary systems to ensure proper operation, especially during failover scenarios. The inifile_checker/replicate parameter in global.ini provides an automated solution to this requirement. When enabled on the primary system, any configuration changes made to ini files on the primary are automatically synchronized to the secondary site. This removes the need for manual configuration replication and helps prevent configuration mismatches that could impact system availability. The parameter only needs to be configured on the primary system, as the secondary system will receive these configuration changes through the normal System Replication process.

Add the following to global.ini:

[inifile_checker]
replicate = true

See SAP Note 2978895 - Changing parameters on Primary and Secondary site of SAP HANA system

Create a SAP HANA Backup on the Primary System

Get a list of all active databases:

hdbsql -jx -i <hana_sys_nr> -u system -d SYSTEMDB "SELECT DATABASE_NAME,ACTIVE_STATUS from M_DATABASES"

For example:

hdbadm> hdbsql -jx -i 00 -u system -d SYSTEMDB "SELECT DATABASE_NAME,ACTIVE_STATUS from M_DATABASES"
Password:
DATABASE_NAME,ACTIVE_STATUS
"SYSTEMDB","YES"
"HDB","YES"

Create a backup of the SYSTEMDB and each tenant database:

The following commands are examples for file based backups. Backups can be performed using your preferred tool and location. If using a filesystem (e.g. /backup) ensure there is sufficient space for a full backup.

Backint

For the SystemDB

hdbsql -i 00 -u SYSTEM  -d SYSTEMDB "BACKUP DATA USING BACKINT ('initial_hsr_db_SYSTEMDB') COMMENT 'Initial backup for HSR'";

For each Tenant DB

hdbsql -i 00 -u SYSTEM  -d <TENANT_DB> "BACKUP DATA USING BACKINT ('initial_hsr_db_<TENANT_DB>') COMMENT 'Initial backup for HSR'";

• Run as <sid>adm

• Ensure that backint has been configured correctly

• You will be prompted to provide a password or alternatively can use -p password

File

For the SystemDB

hdbsql -i <hana_sys_nr> -u system -d SYSTEMDB "BACKUP DATA USING FILE ('/<backup location>/initial_hsr_db_SYSTEMDB') COMMENT 'Initial backup for HSR'";

For each Tenant DB

hdbsql -i <hana_sys_nr> -u system -d <TENANT_DB> "BACKUP DATA USING FILE ('/<backup location>/initial_hsr_db_<TENANT_DB>') COMMENT 'Initial backup for HSR'";

• Run as <sid>adm

• Ensure that a backup location exists with sufficient space and the correct file permissions

• You will be prompted to provide a password or alternatively can use -p password

Stop the Secondary System and Copy System PKI Keys

Stop the secondary system

Stop the hana application on the secondary, as <sid>adm

sapcontrol -nr <hana_sys_nr> -function StopSystem <SID>

Copy the system PKI keys

Copy the following system PKI SSFS key and data files from the primary system to the same location on the secondary system using scp, a shared file system, or an S3 bucket:

/usr/sap/<SID>/SYS/global/security/rsecssfs/data/SSFS_<SID>.DAT
/usr/sap/<SID>/SYS/global/security/rsecssfs/key/SSFS_<SID>.KEY

For example using scp:

hdbadm>scp -p /usr/sap/HDB/SYS/global/security/rsecssfs/data/SSFS_HDB.DAT hdbadm@hanahost02:/usr/sap/HDB/SYS/global/security/rsecssfs/data/SSFS_HDB.DAT
hdbadm>scp -p /usr/sap/HDB/SYS/global/security/rsecssfs/key/SSFS_HDB.KEY hdbadm@hanahost02:/usr/sap/HDB/SYS/global/security/rsecssfs/key/SSFS_HDB.KEY

Configure System Replication on Primary and Secondary Systems

Enable System Replication on the Primary System

Ensure the primary SAP HANA system is started, then as <sid>adm, enable system replication using a unique site name:

hdbnsutil -sr_enable --name=<site_1>

For example:

hdbadm> hdbnsutil -sr_enable --name=siteA

Register System Replication on the Secondary System

Ensure the secondary SAP HANA system is stopped, then as <sid>adm, enable system replication using a unique site name, the connection details of the primary system and preferred replication options.

hdbnsutil -sr_register \
 --name=<site_2> \
 --remoteHost=<hostname_1> \
 --remoteInstance=<hana_sys_nr> \
 --replicationMode=[sync|syncmem] \
 --operationMode=[logreplay|logreplay_readenabled]

For example:

hdbadm> hdbnsutil -sr_register --name=siteB --remoteHost=hanahost01 --remoteInstance=00 --replicationMode=syncmem --operationMode=logreplay

Alternatively, if your setup requires active/active read-enabled access to the secondary:

hdbadm> hdbnsutil -sr_register --name=siteB --remoteHost=hanahost01 --remoteInstance=00 --replicationMode=syncmem --operationMode=logreplay_readenabled

Check SAP Host Agent Version

The SAP host agent is used for SAP instance control and monitoring. This agent is used by SAP cluster resource agents and hooks. It is recommended that you have the latest version installed on all instances. For more details, see SAP Note 2219592 – Upgrade Strategy of SAP Host Agent.

Use the following command to check the version of the host agent, repeat on all SAP HANA nodes:

# /usr/sap/hostctrl/exe/saphostexec -version