Dropping logical-log files

You can use an onparams command to drop logical-log files.

To drop a logical-log file and increase the amount of the disk space available within a dbspace, you can use onparams. The database server requires a minimum of three logical-log files at all times. You cannot drop a log if your logical log is composed of only three log files.

The rules for dropping log files have changed:
  • If you drop a log file that has never been written to (status A), the database server deletes it and frees the space immediately.
  • If you drop a used log file (status U-B), the database server marks it as deleted (D). After you take a level-0 backup of the dbspaces that contain the log files and the root dbspace, the database server deletes the log file and frees the space.
  • You cannot drop a log file that is currently in use or contains the last checkpoint record (status C or L).

To drop a logical-log file with onparams:

  1. Ensure that the database server is in online, administration, or quiescent mode.
  2. Run the following command to drop a logical-log file whose log file number is 21: onparams -d -l 21

    Drop log files one at a time. You must know the log file number of each logical log that you intend to drop.

  3. If the log file has a status of newly Added (A), it is dropped immediately.

    If the log file has a status of Used (U), it is marked as Deleted (D).

  4. To drop a used log file, take a level-0 backup of all the dbspaces.

    This backup prevents the database server from using the dropped log files during a restore and ensures that the reserved pages contain information about the current number of log files.

For information about using onparams to drop a logical-log file, see the IBM® Informix® Administrator's Reference.

For information about using onlog to display the logical-log files and unique ID numbers, see Display logical-log records.

Copyright© 2018 HCL Technologies Limited