Have you ever thought…

What if your system crashes in the middle of a critical transaction?

Have no worries as…

IBM i journaling keeps your operations secure and under control.

Introduction

IBM i Journal Management helps you track changes to important objects in your system. When you use journaling, you create a special object called a journal.

IBM i developers use journals to track files, system activities, and other critical data. This feature makes it easy to:

·       Audit changes

·       Recover data after failures

·       Replicate changes for high availability

In short, journaling keeps your data safe, traceable, and easy to restore.

How Does Journaling Work?

IBM i Journaling lets you track changes to objects and data. It creates a clear audit trail and helps recover data if something goes wrong.

Journaling works by saving every database change in a journal log. Each entry includes:

·       Before and after values of the data

·       Details like time, user ID, and job info

These entries are stored safely on auxiliary storage, so your data stays secure and recoverable.

Why Use Journaling?

Here are the key benefits:

• Quick Recovery – Restore data after unexpected outages.
• Audit Trail – Track who changed what and when.
• Better Security – Monitor system activity.
• Faster Restore – Especially with save-while-active media.
•  Transaction Safety – Recover objects saved with partial transactions.

Objects You Can Journal on IBM i

The following object types of support journaling on IBM i:

• Libraries
•  Database physical files
• Data areas and queues
• Integrated File System objects (stream files, directories, links)

Journal Entries in IBM i

The system records every change made to journaled objects and other notable events. These records are called journal entries. You can also create your own entries for events you want to track.
    

Each entry includes details like:

·       User and job information

·       Program name

·       Date and time of the change

For example, when a database record changes, the journal entry can store the entire record image, not just the changed fields.

Journal Receivers in IBM i

When journaling is active, all changes are stored in a journal receiver. Each journal sends its entries to its attached receiver.

You can manage receivers using System i Navigator or commands like:

• CRTJRN – Create a journal
• CHGJRN – Attach a new receiver
• WRKJRNA – View journal and receiver details

Every entry in the receiver is numbered and includes:

•        Type of change
•        The record changed
•         Details like job, user, and time
      

Setting Up Journaling

Step 1: Create a Journal Receiver
 Use the CRTJRNRCV command to create a journal receiver.
 ✔ Name it like the journal, adding a numeric suffix like 0 or 1.
 ✔ Store the receiver in the same library as the file for easy management.

    
Step 2: Create a Journal
 Use the CRTJRN command to create a journal and link it to the receiver you made in Step 1.

     
Step 3: Start Journaling the File
 Use the STRJRNPF command to link your file to the journal.

✔ Once linked, the system records every add, update, or delete made to the database file.
 ✔ You can also choose to log extra activities like filing open and close by setting options in the command.

Four Basic Journal Entry Categories

Journal entries in IBM i fall into four main categories, each with specific codes:

1. Journal Operations (J): Tracks journal and receiver changes.

Examples:

·       PR – Previous receiver reference

·       NR – Next receiver reference

·       IN – IPL (system start) marker

2. File Operations (F): Logs when files are opened or closed.

Examples:

·       OP – File open

·       CL – File close

3. Record Operations (R): Tracks changes to records.

Examples:

·       UP – Update

·       DL – Delete

·       PT/PX – New record added

4. Commitment Control (C): Handles transaction integrity.

Examples:

·       BC – Begin commitment control

·       SC – Start commit cycle

·       CM – Commit

·       RB – Rollback

Journaling and System Performance
Journaling help prevent data loss if the system stops unexpectedly. It writes changes to a journal receiver right away, keeping your data safe. By default, journal caching is set to *NO, meaning entries are written to disk immediately.

However, journaling adds extra work:

·       More disk activity → Slight performance impact

·       Opening and closing files takes longer

·       IPL (system restart) and ASP vary-on may take more time after abnormal ends

How IBM i reduces impact:

·       Combines before/after images and access path changes into one write

·       Spreads journal receivers across multiple disks for better speed

In short, journaling is powerful for data protection, but plan for extra storage and some performance overhead.

Planning for Journaling

Before you start, decide:
 ✔ Which objects to journal (files, libraries, IFS objects)?
 ✔ Do you need before-images, after-images, or both?
 ✔ Will you use System i Navigator or commands?
 ✔ How many journals and receivers will you create?
 ✔ Do you need remote journaling for replication?
 ✔ Will you combine journaling with save-while-active?

Key Commands for Journal Management

IBM i gives you powerful commands to manage journals:

Ø CRTJRNRCV – Create a journal receiver

Ø CRTJRN – Create a journal

Ø STRJRNPF – Start journaling a physical file

Ø ENDJRNPF – Stop journaling a file

Ø DSPJRN – Display journal entries

Ø DSPJRNRCVA – Show receiver attributes

Ø CHGJRN – Change journal or attach new receiver

Ø WRKJRN / WRKJRNA – Work with journals and attributes

Ø DLTJRN / DLTJRNRCV – Delete journals or receivers

Conclusion

Journal management on IBM i is essential for maintaining data integrity and supporting business continuity. By following best practices—such as proper receiver management, regular backups, and monitoring—you can ensure your system remains dependable and compliant.