Dropping Logical-Log Files

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Dropping 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 or ISA. 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

Ensure that the database server is in online, single-user, or quiescent mode.
Execute 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.
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).
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 on using onparams to drop a logical-log file, see the IBM Informix Administrator's Reference.

For information on using onlog to display the logical-log files and unique ID numbers, see Displaying Logical-Log Records.

To drop a logical-log file with ON_Monitor (UNIX)

Ensure that the database server is in online, single-user, or quiescent mode.
To drop a logical-log file, select Parameters > Drop-Log.
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).
To drop a used log file, take a level-0 backup of all the dbspaces.

Tip:

If the root dbspace has never been backed up, you can drop a used log file immediately.