SUSE Linux Enterprise Server 15 (SLES) not only introduced new software packages - another big update was making those packages more modular. In comparison to predecessor releases, SLES has a generic installation media for the first time. Earlier versions had dedicated images for products such as SLES for SAP or SUSE Manager based on the main distribution.

As a result, this change cut down installation media to about 600 MB, and installs only a basic system without YaST. Additional required packages can be retrieved during the installation via SUSE Customer Center (SCC), SUSE Subscription Manager (SMT), SUSE Repository Mirroring Tool (RMT) or ISO images. Beside the installation DVD (SLE-15-SP1-Installer-DVD-x86_64-GM-DVD1.iso, 660 MB) also a package ISO (SLE-15-SP1-Packages-x86_64-GM-DVD1.iso, 8 GB) is available. Images with the -DVD2.iso postfix only contain source code packages and might be uninteresting for the most installations.

Unfortunately less is not always more, in some scenarios having a bigger images is better.

Products, Modules and Extensions

SUSE classifies software available for SLE into Products, Modules and Extensions. To be honest this is a setup that requires having a second look at it to understand. Maybe the following three rules help you understanding this design:

• On a system, at least one product - consisting of at least one module - is installed
• Products can be extended by optional modules or extensions (which also contain at least one module)
• Extensions usually require additional costs

Products

Modules

Extensions

Less is more? Not really.

Less is not always more. I understand unifying and reducing installation media size to lower maintenance effort. But, for me, the new installation media simply lacks the Basesystem and Server Applications module. Most installations simply require packages from those modules and do not always have the possibility to access a package server during or after the installation. I also think the image name is misleading - better ones would be Minimal ISO or Netinstall ISO.

Especially automatic installations via AutoYaST are imposssible. The reason: missing Basesystem module and autoyast2 package. Depending on the the YaST profile, additional modules (e.g. Server Applications) might be missing, too.

Creating a customized ISO image

The solution is to create a customized ISO image using the mksusecd tool which is available in OpenSUSE and the SUSE Package Hub extension. This tool is able to create a bootable images from folder structures derived from the DVDs. The first step is to install the tool:

1# zypper install mksusecd

Installation DVD 1 should be the starting point, the content of this media needs to be copied into a folder - e.g. by mounting the ISO file:

1$ mount -o loop,ro SLE-15-SP1-Installer-DVD-x86_64-GM-DVD1.iso /mnt
2$ mkdir ~/suse-custom
3$ rsync -aqz /mnt ~/suse-custom

Afterwards, the Packages DVD is mounted and required content is copied. The particular modules and products are stored in subfolders under the root level directory. In this example, the Basesytem and Server-Applications modules are copied:

1$ umount /mnt
2$ mount -o loop,ro SLE-15-SP1-Packages-x86_64-GM-DVD1.iso /mnt
3$ rsync -aqz /mnt/Module-{Basesystem,Server-Applications} ~/suse-custom

The next step is to append module entries to the media.1/products file. Every line consitsts of a path and the module description. These information can also be found in the same file on the Packages DVD - so you can copy them easily:

1/ SLES15-SP1 15.1-0
2/Module-Basesystem Basesystem-Module 15.1-0
3/Module-Server-Applications Server-Applications-Module 15.1-0

Finally, mksuse creates a new images. Creating a cryptographic checksum is basically a good idea if you plan to transport the file to additional systems:

 1$ mksusecd --create SLE-15-SP1-Pinkepank-x86_64-DVD.iso ~/suse-custom
 2Repositories:
 3  SLES15-SP1 [15.1-0]
 4  Basesystem-Module [15.1-0]
 5  Server-Applications-Module [15.1-0]
 6assuming repo-md sources
 7El-Torito legacy bootable (x86_64)
 8El-Torito UEFI bootable (x86_64)
 9building: 100%
10calculating sha256...
11$ sha256sum SLE-15-SP1-Pinkepank-x86_64-DVD.iso > SLE-15-SP1-Pinkepank-x86_64-DVD.iso.sha256

Packages DVD content

The following table shows available content on the Packages DVD: