DC/UCF Concepts › Logging Options › Using Sequential Files › Logging to Sequential Disk Files

Logging to Sequential Disk Files

When logging to sequential disk files, you can assign the log either to a single disk file or to two alternate disk files.

Logging to a Single File

When logging to a single file, the system writes all log records to one sequential file. When the file becomes full, the system performs the following tasks:

1. Sends a message to the operator's console describing the condition
2. Continues to write to the file, overwriting records previously written to the file

The DC/UCF system writes log records to the beginning of the file at each system startup. If log records are to be saved, the appropriate operating system utility must be used to offload the file when the system is shut down.

Logging to Alternate Files

When logging to alternate files, the system writes log records to one file at a time. When the active file becomes full, the system performs the following tasks:

1. Closes the active file.
2. Sends a message to the operator's console describing the condition.
3. Opens the other file and begins logging to it. The full file can be offloaded while the system writes log records to the other file.

A full log file should be offloaded immediately. If the alternate file becomes full before the first (full) file is offloaded, the system begins logging to the first file again, overwriting records previously written to the file.

The DC/UCF system writes log records to the beginning of the first file at each system startup. If log records are to be saved, the appropriate operating system utility must be used to offload both files when the system is shut down.