Create custom rocky ISO

Hello rocky community,

I would like to make a personal project to test and learn more about customizing linux distro.
I’d like to make a network firewall/router out of rocky linux. I think it will be fun to experiment.

I’d like some advices on how to customize iso and where to start.

My first idea is to unpack rocky iso, create a kickstart and automate at maximum installation. Then put the kickstart directly in the iso make it boot directly with the kickstart. Is it a good idea or do you see any smarter/simpler way to do this ? Let me know :slight_smile:

Thanks for reading

You can use mkksiso to add a kickstart to a given ISO. There’s no need to unpack it.

dnf install lorax -y
mkksiso /path/to/kickstart /path/to/iso /path/to/output.iso

Oh that’s a nice tool, thanks ! i’m used to the debian’s preseed way where you have to unpack and repack to automate installation

For me that fails with an error.

Command I executed:
mkksiso kick Rocky-9.1-x86_64-minimal.iso Rocky-9.1-x86_64-minimal-LG.iso


libisofs: WARNING : Found hidden El-Torito image. Its size could not be figured out, so image modify or boot image patching may lead to bad results.
xorriso : NOTE : Detected El-Torito boot information which currently is set to be discarded
xorriso : SORRY : Cannot enable EL Torito boot image #1 because it is not a data file in the ISO filesystem

I therefore would like to ask the makers of that ISO file to make it mkksiso-friendly. Thanks.

Despite the messages from the command, it is not an error. They are warnings. The ISO does get made with the kickstart, but is only UEFI bootable as a result. To avoid this so it’s bootable on both MBR and UEFI, you will need to obtain an updated ISO.

The latest ISO’s are here: Index of /pub/rocky/9/isos/x86_64/


@nazunalika I still see the mentioned warning. Are there any plans to update the IOS images at Index of /pub/rocky/9/isos/x86_64/?

There are updated images there. They have dates of their creation in their name. We don’t replace the original ISO’s.

See this page for more information on the formats you may see in the ISO names: Rocky Linux ISOs and Images - Rocky Linux Wiki

Thanks, totally missed the ISO’s with the date.
Is there any reason why there are no updated boot.iso images?

Rebuilding the boot.iso’s require us to run lorax on all architectures. The boot images are also in pristine condition and did not suffer from the problems in the original dvd and minimal ISO’s. And since the boot.iso does not have any packages on them to install, it did not make sense to build new ones.

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