Changing Logical-Log Configuration Parameters

The following configuration parameters affect the logical-log file and how the database server works with it:

• LOGSIZE
• LOGFILES
• LTXHWM
• LTXEHWM

The following sections explain the procedure for changing each of these configuration parameters. For more information on these parameters, see the chapter on configuration parameters in the IBM Informix: Administrator's Reference.

The LOGFILES parameter determines the number of logical logs that are created during the server's first initialization. It is not used during subsequent server startups unless the disk space is being reinitialized. Its value should remain constant over the life of a server instance.

The values of LOGSIZE, LTXHWM, and LTXEHWM can be modified at any time, even with the server on-line.

To modify these parameters with the server off-line, use a text editer to change their values in the ONCONFIG file. You must be logged in as root or informix to modify this file. These changes will take effect during the next server startup.

To modify these parameters with the server in quiescent or on-line mode, use the onutil SET command. For example:

% onutil
1> SET LOGSIZE 3500;
Dynamic Configuration completed successfully.
2> SET LTXEHWM 75;
Dynamic Configuration completed successfully.
3> SET LTXHWM 70;
Dynamic Configuration completed successfully.

The changes shown above are not persistent. If the server is restarted, the new values will be lost. To make the changes persistent across server restarts, use the PERSISTENT keyword, as in:

% onutil
1> SET LTXHWM 55 PERSISTENT;
Dynamic Configuration completed successfully.

The PERSISTENT keyword causes the ONCONFIG file to be rewritten with the new parameter value.

For more information on the onutil SET command, see the utilities chapter in the IBM Informix: Administrator's Reference