CentOS

Is it possible to build a CentOS-8-x86_64-DVD.iso with maximal 4.2GB size? In my case it is not possible to use an USB Stick.

I was a little surprised that there was not a "standard" sized DVD image either.

From Installation Notes :

The Binary DVD ISO image is larger than 4.7 GB, and as a result, it might not fit on a single-layer DVD. A dual-layer DVD or USB key is recommended when using the Binary DVD ISO image to create bootable installation media. You can also use the Image Builder tool to create customized RHEL images.

Yes, we all read the installation notes.
There are MANY people that absolutely cannot use any USB drive in their computer.
These computers are also NOT connected to the internet.
They also cannot write or read read dual-layer DVD disks.
Many of us do not want to, or don't have the ability to "just go ahead and remaster and build a custom ISO".

So we are looking for a solution that will very likely involve a kind soul building a standard size DVD ISO, and an accompanying disk, probably with RPMs to be added after the main installation is complete.

if you don´t have an USB, a DVD drive or an internet connection, do a cross install, boot rescue and run dracut

or try NetBSD, it was supposed to run on toasters, though toaster these days are IoT

There are MANY people that absolutely cannot use any USB drive in their computer.
These computers are also NOT connected to the internet.
They also cannot write or read read dual-layer DVD disks.

I suspect MANY is an exaggeration.

I'm sure the CentOS team would take patches for a verified process to produce smaller media. It's on the list but there are more important things to prioritise first - not least building and releasing 8.1.

Some "person" in his infinite wisdom, decided to scrap the minimal .iso image and only provide an oversized DVD image

While there have been a lot of complaints, bug report, bugzilla reports and a lot of rants, there has been no change and we are all forced to download all that garbage.

Maybe the next awesome idea that this "person" has, is to load the DVD with some bundleware apps, maybe a facebook app combined with lots of google apps that can't be uninstalled.

Who knows, maybe things will improve in centos 8.1

Some "person" in his infinite wisdom, decided to scrap the minimal .iso image and only provide an oversized DVD image

No. No-one decided that. What the problem is is that CentOS 8 is radically different and none of the old tools understand what it's done to repos. See "modules". That means that it is now not possible to generate a minimal iso using the old methods so we are currently stuck issuing exactly the same media choices as upstream at RHEL who also only offer 1 gigantic iso or a netinstall.

Please don't spread FUD when you do not know the facts.

I never said centos was at fault

Just buy some dual layer DVD media and be done with it, and if necessary an appropriate writer for crying out loud. Though I have not seen a DVD writer that can't do dual layer in many years now. If you are working in an environment where you are not allowed to boot from USB for any reason, then you need to accept the small cost of sourcing dual layer DVD media. I can get a spindle of 10 Verbatim branded ones from Amazon prime for £10 next day or only £8 if Philips branded ones will do the trick.

If that is not possible then set up for a network install. I have not seen a machine incapable of net booting in over fifteen years now.

If your target machine won't work with a dual layer DVD, can't be netbooted and you are not allowed to boot from USB then I would kindly suggest that it is time for it to be retired from active service because it is a hunk of junk.

I would note that for the vast majority of people a single DVD image is wildly preferable than having it split over more than one, with the vast vast majority of people either booting from USB, using virtual media, being able to write a dual layer DVD or do a net install.

Finally I would note that the maximal size of a single layer DVD is 4.7GB not 4.2GB.