SEP sesam Extension for Informix

(C)SEP AG

Copyright 1999-2011 by SEP AG. All Rights reserved.

Any form of reproduction of the contents or parts of this manual is allowed only with the express written permission from SEP AG. When compiling and designing user documentation SEP AG uses great diligence and attempts to deliver accurate and correct information. However, SEP AG cannot issue a guarantee for the contents of this manual.

Introduction

SEP sesam online backup for Informix (sib) provides a XBSA interface between Informix and SEP sesam for saving data of Informix databases to SEP sesam Server. XBSA API specifies the access from Informix onbar utility to a backup application. SEP sesam will manage the whole backup media handling like loading the correct tapes, whereas ONBAR decides which data has to be saved or recovered. This document provides information about the sesam specific parts of Informix backups. It's not an Informix/ONBAR administration guide. Please read Informix documentation of ONBAR to get familiar with Informix's backup and recovery concepts and tools.

System requirements

• Informix Dynamic Server 7/9/2000 on Linux, Unix or Windows
• SEP sesam Version 3.2 or higher
• SEP sesam Extension for Informix
• the standard SEP sesam Backup Client is already installed
• working SEP sesam file system backups for this client

Installation

Installation on Linux or Unix

The SIB packet includes only one shared library which Informix server loads dynamically during backup or restore. The library has to be copied to Informix server and the full path to it has to be specified under BAR_BSALIB_PATH in the ONBAR configuration file.

For installation we assume the following environment. Please adjust the paths and variables according to your needs.

• INFORMIXDIR=/opt/informix
• ONCONFIG=/opt/informix/etc/onconfig

Installation steps:

• First verify that the standard SEP sesam Backup Client is already installed
• File system backup should work with this SEP sesam Client
• Login as informix user
• Create a new directory sib in \$INFORMIXDIR
• Unpack the file <OS>_ssib_x.x.x.x.tgz there
• Create a symbolic link in \$INFORMIXDIR/lib to the unpacked library file ibsad001.so. If file already exists, rename it first.

• PATH environment variable should include \$INFORMIXDIR/bin
• Check the backup/restore specific entries in the ONCONFIG file:

BAR_BSALIB_PATH Path to installed SEP sesam library

Example (Linux):

Installation on Windows

Installation steps:

• First verify that the standard Windows SEP sesam Backup Client (x64 or x86) is already installed
• File system backup should work with this SEP sesam Client
• Login as informix user
• Extract the appropriate libbsa.dll from SEP download SEP sesam Extension for Informix - Windows (ZIP archive) - either x64 or x86 and copy it into SEP sesam gv_ro_bin:bin\sesam directory.
• Edit the instance specific onconfig file and set the BAR_BSALIB_PATH to the libbsa.dll.

Example (Windows):

• INFORMIXDIR=C:\PROGRA~1\IBM\Informix\11.70
• ONCONFIG=%INFORMIXDIR%\etc\ONCONFIG.ol_myinst

Common Installation Steps

To set the version of XBSA specification SEP sesam supports, the following entry has to be inserted in table bar_version on sysutils database.

Instead of inserting this entry into database you can also adopt the INFORMIX template file.

• Copy template file \$INFORMIDIR/etc/sm_versions.std to \$INFORMIXDIR/etc/sm_versions
• Add the following line 1|1.0.1|sesam|1|

Configuration on SEP sesam Server

Create a new backup task for the Informix server with task type Informix. For backup source you must specify the Informix Instance. The instance should map to the instance which is used during ONBAR backup command.

Configuration on Informix server

To give ONBAR the necessary information to connect to SEP sesam, the following environment variables have to be set.

Mandatory parameters

• INFORMIXDIR (set by Informix installation).
• SESAM_SERVER=<Name of SEP sesam Server>
• SESAM_JOB=<Jobname of Informix backup> # Name of an already configured task on SEP sesam Server with task type Informix
• SESAM_POOL=<Media pool name> # Name of an already configured media pool on SEP sesam Server

Optional parameters

• XBSA_TRACE=<Trace level> (0|1|2) (if set with +10000000 then process logs to STDERR, e.g. 'set XBSA_TRACE=10000002')
• XBSA_LOGFILE=<Name of trace file>

Although XBSA_TRACE XBSA_LOGFILE are not mandatory, they should be set to get information in case of a problem during backup or restore. For a restore only SESAM_SERVER and SESAM_JOB are mandatory.

ONBAR Backup Configuration

The following examples show, how backup or restores can be started on Informix server. They do not cover all functions of ONBAR, but should give some hints for using ONBAR and SEP sesam together.

• Backup of tablespace dbspace01

The commands shown in the following example:

Perform a level 0 backup of "'dbspace01"' on an Online Dynamic Server instance named venus. Backup all logical log files associated with dbspace01, close and backup the current logical log

onbar -b -L 0 dbspace01 onbar -b -l -c

ONBAR Restore Configuration

ONBAR commands to restore data backed up. The shared XBSA library translates Informix names passed by ONBAR into SESAM server save set (a set of files) for retrieval from the SESAM server's database and restoration to Informix.

Physical Restore:

onbar -r -p

Physical restores replace lost or corrupted storage spaces from SESAM backup media.

If a critical storage space is damaged because of a disk failure or corrupted data, Dynamic Server goes off-line.

If a disk failure or the corruption of data does not cause the database server to go to off-line mode you can restore any noncritical storage spaces.

Logical Restore:

Logical restores recover the server transactions made since the last storage space backup, followed by a rolling forward of the logical logs backed up for the storage space. If different backup sessions are involved, the log rolls forward transactions made since the backup time recorded for each storage space are restored.

Combined Restore:

Combined restores allow you to issue a single command to perform a physical restore immediately followed by a logical restore. For finer control, use the onbar -b -l -s command to salvage the logs, then the onbar -r -p command to perform only a physical restore, and then the onbar -r -l command to perform only a logical restore.

Point-in-time Restore:

Point-in-time restores involve performing a whole-system, physical restore of Informix data from a whole-system-backup to a specified time instead of the default, which is time of the last Informix backup.

There are two different kinds of restore you can perform in dependence of Informix Dynamic Server current mode. If the server is in quiescent mode or is on-line, you can perform a warm restore (Use the -O option to restore an on-line storage space). Otherwise, if server resides in off-line mode, the restore operation is called a cold restore.

for example Logical Log:

Backup and Restore Overview

Here the commands are given for the following scenarios.

Backup of database

Complete backup of database (if necessary start the database with oninit -v)

Backup of a single dbspace

Logical Logfiles Backup

Database Restore

Restore of the whole database (cold restore)

Restore of the down dbspaces and corresponding logical logs (cold)

Restore of the down dbspaces without logical logs (cold)

Restore of single dbspaces

Restore of the logical logs (for dbspaces, wich have been restored physically)

Trouble shooting

Specific Error Messages

Error message when executing oninit

Take a look at this article: http://www-01.ibm.com/support/docview.wss?uid=swg21501819

Error during first backup attempt

Create missing file, here C:\PROGRA~1\IBM\Informix\11.70\etc\ixbar.0 ( See IC50591: IXBAR.FILE IS REQUESTED DURING AN EXTERNAL RESTORE ALTHOUGH NO BACKUP WAS CREATED )

Error 131 during first logical logs backup attempt

Set LTAPEDEV in ONCONFIG file to a valued different to '/dev/null' or 'NUL', e.g. 'LTAPEDEV \\.\TAPE0' for Windows. See IBM Informix Dynamic Server LTAPEDEV

General trouble shooting

• ensure, that the following environment variables INFORMIXDIR, INFORMIXSERVER, ONCONFIG, ROOTPATH are correctly set.
• check the messages on SEP sesam Server.
• more information can be found in the logfiles of ONBAR and SIB.
• SEP recommends using only one single log file for ONBAR and XBSA messages.
• Then you can see all calls from database and sesam in correct order.
• For this set environment variable

• All SIB (sesam) messages have the prefix SIB.
• For more information XBSA_TRACE can be set to 2, but then the logfiles can become quite large.
• To activate the ONBAR log, edit the following line in the onconfig file:

Further Links/Literature

• SEP sesam Extension for Informix
• IBM Informix Dynamic Server Backup and Restore Guide
• 'Backup Services Application Programmer's Interface'
• 'System Management: Backup Services API (XBSA)'