Before you start using ON-Bar for data recovery with your Informix database, you need to make sure that it is correctly set up. You specify configuration information for ON-Bar in the ONCONFIG file and as environment variables.

How you configure ON-Bar partly depends on your approach to data recovery. Therefore, make sure that you have worked out your approach first. Refer to Approach to Database Backup (ON-Bar) and Approach to Logical-Log Backup (ON-Bar).

1. Decide what kind of storage manager you intend to use with ON-Bar .

You can use the Informix Storage Manager (ISM), which comes with your Informix database server, or a third-party storage manager. You must make sure that the storage manager you choose is compatible with:

· Your storage devices (that is, disk and tape drives, and so on)

· Your version of ON-Bar

For more information about storage managers, including how to configure ISM, see the Informix documentation and SAP Note 74440.

ISM is more tightly integrated in ON-Bar than third-party storage managers. Therefore, if you use ISM, be sure to complete the next few steps.

2. Set the environment variables required by ON-Bar , depending on which storage manager you are using.

If you are using ISM, set the environment variables ISM_COMPRESSION and ISM_ENCRYPTION , which determine how ISM backs up data. For more information, see the Informix documentation.

3. Set the required variables in the ONCONFIG file, depending on which storage manager you are using. For more information, see the Informix documentation.

Summary of ONCONFIG File Parameters for ON-Bar

Parameter	Determines
BAR_MAX_BACKUP	Degree of parallelism used by ON-Bar
BAR_ACT_LOG	Path to the ON-Bar activity log
BAR_DEBUG_LOG	Path to the ON-Bar debug log
BAR_DEBUG	Degree of detail held in the ON-Bar debug log
BAR_RETRY	How often ON-Bar retries to send data to or receive data from the storage manager
BAR_XFER_BUF_SIZE	Size of the buffer used for exchange between ON-Bar and the storage manager
BAR_NB_XPORT_COUNT	Number of buffers used for exchange between ON-Bar and the storage manager
BAR_BSALIB_PATH	Path of the shared library used as interface between ON-Bar and the storage manager
LTAPEDEV	Whether or not logging is switched on. See caution below.
ALARMPROGRAM	Event alarm, for example, used to start a logical-log backup when logs reach a certain fill level.
LOG_BACKUP_MODE	Mode for logical-log backup.
LBU_PRESERVE	This is the most important prevention against emergency logical-log backups. If other measures fail, this parameter always prevents the logical log filling completely. It specifies how many logical-log files the database server always preserves (that is, avoids writing logging data to). Set it as follows: LBU_PRESERVE 1



Do not set LTAPEDEV to blank or /dev/null (UNIX) or nul (NT) if you want to be able to perform a restore of your system up to the time of failure. If you specify a null value, logical-log backups are not performed and are therefore not available if a restore is necessary.

When you have finished editing the ONCONFIG file, you have to stop and restart both the SAP System and the Informix database server for the changes to take effect. You can check the contents of the file in SAPDBA. Refer to Listing System Information with SAPDBA.



The entries in your ONCONFIG file relevant to ON-Bar should look similar to the following example for UNIX:

# Backup/Restore Variables for ON-Bar

BAR_ACT_LOG /tmp/bar_act.log # path of ON-Bar activity log

BAR_MAX_BACKUP 0 # Maximum no. of parallel onbar_d processes

BAR_RETRY 1 # Number of times to retry failures

BAR_NB_XPORT_COUNT 10 # No. of transport buffers

BAR_XFER_BUF_SIZE 31 # Size of each transport buffer

RESTARTABLE_RESTORE OFF # Enables restartable restore

# Use either LOG_BACKUP_MODE in IECC or ALARMPROGRAM, not both

LOG_BACKUP_MODE CONT # Use IECC to set value: CONT or MANUAL

ALARMPROGRAM /usr/informix/etc/log_full.sh

BAR_BSALIB_PATH /usr/lib/ibsad001.so # XBSA shared lib path

#Informix Storage Manager Variables

ISM_DATA_POOL ISMData

ISM_LOG_POOL ISMLogs

#Log Archive Tape Device

# Do not set LTAPEDEV to blank or /dev/null

LTAPEDEV /dev/tapedev

LTAPEBLK 16

LTAPESIZE 10240

If you are using ISM, check especially the parameters towards the end of the file marked Informix Storage Manager Variables in the above example.

4. If you use a storage manager other than ISM, follow the configuration instructions supplied. Make sure that the location of the XBSA library is specified to ON-Bar . For more information, see the Informix documentation.
5. Check the contents and location of the main files for ON-Bar .

Main Files for ON-Bar

File Name	Comments
Informix message log	Contains all messages generated by database server. Allows you to determine if a problem is on the database server side or the client side (that is, ON-Bar or the storage manager). Use Listing System Information with SAPDBA to view the message log. The name of the file is specified by the MSGPATH parameter in the ONCONFIG file.
ONCONFIG file	Contains general configuration information for the database server, including parameters prefixed BAR_ , which are specific to ON-Bar (see the example above). Use Listing System Information with SAPDBA to view the ONCONFIG file. The name of the file is normally onconfig.<hostname>.sid and it is normally in the directory $INFORMIXDIR/etc (UNIX) or %INFORMIXDIR%\etc (NT).
ON-Bar activity log	Contains all messages about activity in ON-Bar . It is very useful for solving problems. The name of the file is specified by the BAR_ACT_LOG parameter in the ONCONFIG file.
ON-Bar debug log	Contains detailed debugging information to help you solve a problem together with the Informix hotline. The name of the file is specified by the BAR_DEBUG_LOG parameter in the ONCONFIG file.
ON-Bar emergency boot file	Contains backup information similar to that in the ON-Bar catalog files for use in a restore. The file is called ixbar.<server number>
Server boot file	Contains information required to start the database server. The file is called oncfg_<server name>.<server number>

For more information, see the Informix documentation and SAP Note 78884.

6. Test ON-Bar with your chosen storage manager before you go live.

You can now start using ON-Bar to create backups of your database and logical log. Refer to:

• Approach to Database Backup (ON-Bar)
• Approach to Logical-Log Backup (ON-Bar)

Informix documentation at http://www.informix.com