I wanted to test Oracle's Enterprise Linux (Unbreakable Linux). On the website of Oracle I couldn't find one big iso, so I downloaded the 5 CD iso images.
As I don't have enough computers, I use VirtualBox. Since I thought that it was not possible to install an OS via multiple iso images with VirtualBox, I did the following:
I merged the 5 iso images into one big iso image. Don't worry, this doesn't require complex manipulations, this is what I did:
1. copied the first iso to a new iso image: "cp first.iso new.iso"
2. executed the next command: "cat second.iso >> new.iso"
This just appends the second iso image to the copy of the first iso image.
Repeat this for the other iso images ("cat third.iso >> new.iso", "cat fourth.iso >> new.iso", and "cat fifth.iso >> new.iso")
Unfortunately, during the installation of Enterprise Linux, the wizard kept asking for Installation CD 2... No luck for me.
Back to installing via the 5 iso images then. And after a tip I found out that it is easy to switch from iso image during the installation.
First make sure that all iso images are loaded in VirtualBox.
Then create the a virtual machine and let it boot from the first iso image.
When the install wizards asks for the second iso image, click Devices in the VirtualBox menu, and select Unmount CD/DVD-ROM.
Then Devices > Mount CD/DVD-ROM > CD/DVD-ROM Image and select the second iso image.
Simple as that... perhaps I should try reading manuals...