Split Mirror Backup: Software Configuration

This section describes the software configuration for split mirror backup:

At least the client software and SQLPLUS components of the Oracle database software must be installed on the backup host.
The Oracle home directory structure must correspond to the SAP standard installation required by BRBACKUP.

UNIX	Windows
$ORACLE_HOME/dbs	%ORACLE_HOME%\DATABASE
$ORACLE_HOME/bin	%ORACLE_HOME%\BIN
$SAPDATA_HOME/sapbackup	%SAPBACKUP%
$SAPDATA_HOME/saparch	%SAPARCH%
$SAPDATA_HOME/sapreorg	%SAPREORG%
$SAPDATA_HOME/sapcheck	%SAPCHECK%
$SAPDATA_HOME/saptrace	%SAPTRACE%

Note

BRBACKUP must be able to access the control files on the backup server created by the SQL command alter database backup controlfile to <filename> on the production server.

BRBACKUP tries to copy the control files to the backup server using the rcp, scp, or ftp command - depending on the value of stage_copy_cmd - and the host name for the HOST_NAME field of the V$INSTANCE view.

Alternatively, you can use Network File Systems (NFS) or Windows network drive to mount the sapbackup directory from the production server to the backup server.

For more information, see SAP Note 156704 Information published on SAP site .

The Oracle and BRBACKUP profiles should be available in $ORACLE_HOME/dbs or %ORACLE_HOME%\DATABASE.
Set the backup_type parameter in the init<DBSID>.sap profile to offline_split |online_split|offline_mirror|online_mirror|oncons_split|oncons_mirror|offstby_split|offstby_mirror.
To establish the connection between the backup server and the production server, you must define the profile parameter primary_db for the SQLNET connection. Before this, you must perform the following steps on the primary database host:
- Create an Oracle password file:
  
  orapwd file=<ORACLE_HOME>/dbs/orapw<DBSID> password=<SYS password> entries=10
- Set the remote_login_passwordfile parameter to exclusive in the init<DBSID>.ora profile or spfile.
- Give the system user SYSOPER authorization in the production database. Start SQLPLUS as user SYS and execute the following Oracle command:
  
  SQL> connect / as sysdba
  
  SQL> grant sysoper to system;
- If needed, change the password for the system user:
  
  SQL> alter user system identified by <password>;
  
  For more information, see SAP Note 131610
The SYSOPER authorization and the password file are only required to stop the primary database for the offline split. For an online split, the standard remote connection using the connection string specified in the primary_db parameter is sufficient.

The primary database should remain open during the entire backup.
Make sure that the directory /usr/sap/<SAPSID>/SYS/exe/run or \\<Host name>\sapmnt\<SAPSID>\SYS\exe\run is accessible from the backup host and that it contains at least the programs BRBACKUP, BRCONNECT, and BRTOOLS (and optionally other BR programs).

Note
Normally make sure that the paths of all database files accessed by the production database and backup database are identical, although this is not absolutely essential.

You can mount the database files on the backup host in a different SAPDATA_HOME directory by using the init<DBSID>.sap parameter orig_db_home. By using this parameter you can even mount the split-off files on the same host.
The manufacturer of the external backup tool should install and configure the BACKINT interface on the backup host, if used.
To use the Oracle Recovery Manager (RMAN) for a split mirror backup, you need to set one of the following three possibilities in the initialization profile init<DBSID>.sap parameter file:
- backup_dev_type = rman_util|rman_disk|rman_stage
- backup_dev_type = tape|tape_auto|tape_box|pipe|pipe_auto|pipe_box
  
  tape_copy_cmd = rman|rman_dd
- backup_dev_type = disk
  
  disk_copy_cmd = rman|rman_set

Profile Parameters and Command Options for init<DBSID>.sap

Make sure that you have set the following parameters in the initialization profile init<DBSID>.sap:

backup_type = offline_split|online_split|offline_mirror|online_mirror|offstby_split|offstby_mirror|oncons_split|oncons_mirror
Split command scenario using offline_split, online_split, offstby_split, or oncons_split:
- split_cmd = "<split_cmd> [$]"
  
  <split_cmd> is a program or shell script called by BRBACKUP to split the mirror disks.
- resync_cmd = "<resync_cmd> [$]"
  
  <resync.cmd> is a program or shell script called by BRBACKUP to resynchronize the mirror disks. This parameter must be set so that BRBACKUP performs the resynchronization.
  
  At runtime, BRBACKUP replaces the optional character $ with the name of the text file that contains the names of all files to be split or resynchronized.
  
  Note
  If split_cmd/resync_cmd is completed successfully, an exit code of 0 is returned. Only messages beginning with #INFO are accepted, that is, these are the only messages not interpreted as error messages. If the command is not successful, a return code of > 0 is returned as well as messages describing the cause of the error.
SPLITINT scenario using offline_mirror, online_mirror, offstby_mirror, or oncons_mirror:
- split_options = "<split_options>"
  
  This defines the additional options used to call SPLITINT. Your SPLITINT vendor can tell you how to set them.
- split_resync = no|yes
  
  This controls whether the mirror disks need to be resynchronized immediately after the backup has finished.
primary_db = <conn_str>

<conn_str> is a connection string to the production database to connect from the backup server to the production server. The connections are defined in the Oracle configuration file tnsnames.ora.
standby_db = <conn_str>

<conn_str> is a connection string to the standby database to connect from the backup server to the standby server. The connections are defined in the Oracle configuration file tnsnames.ora. BRBACKUP needs SYSDBA privileges for this connection so as to be able to restart the standby database. For more information, see the Oracle password file above.
The BRBACKUP call is as follows:
- Split command scenario:
  - Online backup of mirror disks:
    
    brbackup -t|-type online_split|oncons_split
  - Offline backup of mirror disks:
    
    brbackup -t|-type offline_split|offstby_split
- SPLITINT scenario:
  - Online backup of mirror disks:
    
    brbackup -t|-type online_mirror|oncons_mirror
  - Offline backup of mirror disks:
    
    brbackup -t|-type offline_mirror|offstby_mirror
For more information, see -t|-type. This command line option overrides the backup type set in the backup_type parameter in the init<DBSID>.sap profile.
pre_split_cmd and post_split_cmd

You can use these parameters to execute external commands before or after the BRBACKUP disk split.
pre_shut_cmd and post_shut_cmd

You can use these parameters to execute external commands before or after the database is stopped for an offline backup with BRBACKUP.