If you're coming to IBM i from a Windows or Linux background, the term Image Catalog might sound a little unusual. But don’t worry - by the end of this blog, you'll not only understand what it is, but also how to use it confidently.

What is an Image Catalog?

Think of an Image Catalog like a virtual CD/DVD wallet.
Just like you might have a folder on Windows with ISO files (disk images) and a tool like Daemon Tools or Virtual CloneDrive to mount them, IBM i uses Image Catalogs and virtual optical devices to achieve the same thing.

An Image Catalog is simply a list of ISO or SAVF image files that you can load and access as if they were inserted into a DVD drive.

Why Use Image Catalogs?

You’d typically use an image catalog to:

• Install PTFs (Program Temporary Fixes)
• Install Licensed Programs (e.g., via .iso or .bin images)
• Perform system upgrades
• Mount IBM i install media virtually—especially useful on systems with no physical media drives

Step-by-Step: Creating and Using an Image Catalog

Here’s a beginner-friendly guide:

1. Create the Image Catalog

    CRTIMGCLG IMGCLG(MYISOCLG) DIR('/myimages') TYPE(*OPT)

• IMGCLG – Name of the catalog
• DIR – IFS directory where your ISO files are located
• TYPE(*OPT) – Specifies it’s for optical media

Tip: If the directory doesn't exist, create it with MD DIR('/myimages')

2.       Add an Image File to the Catalog

ADDIMGCLGE IMGCLG(MYISOCLG) FROMFILE('/myimages/rocket.iso') TOFILE(ROCKETISO)

• FROMFILE – Path to your ISO file in the IFS
• TOFILE – Alias you want to give it inside the catalog. It is only for organizational purposes within the catalog. It’s like tagging an image for easy reference in the catalog listing.

3.       Create a Virtual Optical Device

CRTDEVOPT DEVD(VRTCD01) RSRCNAME(*VRT)

This creates a virtual DVD drive on IBM i.
On Windows, this is like creating a virtual drive letter (e.g., "E:") to mount ISOs.

4.       Associate the Catalog with the Virtual Device

LODIMGCLG IMGCLG(MYISOCLG) DEV(VRTCD01) OPTION(*LOAD)

• This loads the catalog and mounts the image into the virtual DVD drive

Note : If you're reusing a device, make sure it’s varied off before loading:

VRYCFG CFGOBJ(VRTCD01) CFGTYPE(*DEV) STATUS(*OFF)

5.       Confirm It's Mounted

WRKOPTVOL

You should see the volume label of the mounted ISO - just like when you insert a disc into your Windows DVD drive and see it under "This PC".

Sample Use Case: Install a Licensed Program from ISO

Once the ISO is mounted:

RSTLICPGM LICPGM(4RICLUS) DEV(OPT01) OPTION(*BASE)

This command installs a specific licensed program (like Rocket iCluster) from the mounted ISO. Replace the LICPGM number and OPTION as per your product.

Sample Use Case 2: Use LODRUN to Launch an Installer Automatically

In some cases, the ISO media contains an installer program that should be launched automatically—this is where LODRUN comes in.

LODRUN DEV(OPT01)

This is like double-clicking setup.exe on a CD in Windows.

It does the following:

• Loads the image catalog
• Mounts the volume
• Automatically runs the install program defined on the optical media (usually QINSTLPGM)

Tip: Not all ISOs support LODRUN. It works when the install media includes metadata to indicate what should be run automatically.

Summary of Use Cases

Common Gotchas

• Virtual device not varied on: If you get errors during mount, check device status with WRKCFGSTS CFGTYPE(*DEV)
• Wrong path or directory permissions: Make sure ISO files are uploaded correctly into the specified IFS directory
• Previous mount not cleared: Run LODIMGCLG OPTION(*UNLOAD) to unload previous image catalog

Analogy for Windows Users

Conclusion

IBM i's Image Catalog system may seem a little old-school at first, but it's a powerful and flexible way to manage installation media - especially when working with remote or cloud-hosted partitions.

If you've ever mounted an ISO on Windows, you're already halfway there. With just a few commands, you can get your IBM i system to do the same.