Siebel Server Installation Guide for Microsoft Windows > Creating the DB2 Universal Database for Windows and UNIX > Creating the Database >

Physical Device Layout

To make sure that your database performs well, create at least one container for each available logical or physical disk device. Data and log devices should reside on different disk spindles to reduce contention between random and serial I/O. All DB2 devices should reside on different disk spindles to minimize I/O contention. When this approach is not possible, spread devices containing database objects that are often used together across different spindles. These objects include tables, their indexes, and commonly joined tables.

NOTE:  If you are using a high performance disk subsystem, you might choose a different physical device layout. Consult your DBA and the disk subsystem vendor for the optimal setup.

Allocating Sufficient DB2 Database Log Space

You must create database transaction logs large enough to support various large transactions used by the Siebel software. On DB2, three parameters affect the amount of log space reserved:

LOGFILSIZ. The size of the log file.

LOGPRIMARY. The number of log files to preallocate and use.

LOGSECOND. Extra log files that are allocated only if they are needed for a large transaction.

To run on a large system, create approximately 1 GB of total log space. It is recommended that you create 25-50 primary log files of 32 MB each. This is accomplished by setting the LOGFILSIZ database configuration parameter to 20000 and the LOGPRIMARY parameter to 25-50. In addition, to support very large transactions, set the LOGSECOND parameter to 128 minus the value of LOGPRIMARY.

Smaller systems may use less log space.

Log File Archiving

The database parameter LOGRETAIN is not enabled by default; this parameter may be important to you. When LOGRETAIN is set to OFF, the log files are reused in a circular fashion. This means that roll-forward recovery cannot be used. When LOGRETAIN is set to RECOVERY, all log files are kept on the system for the administrator to archive and delete.

If LOGRETAIN is set to NO, you can do only backup (restore) recovery and cannot do roll-forward recovery. This may have implications for your disaster recovery process related to your production Siebel Database Servers.

It is recommended that your database administrator (DBA) review the setting for this parameter.

 Siebel Server Installation Guide for Microsoft Windows 
 Published: 25 June 2003