I recently tried to reboot from a CD/DVD. A message flashed on the screen VERY briefly indicating that (if I understood the split second message) the driver for the CD/DVD drive could not be found. The boot continued with the version of CentOS on the hard drive.

Someone told me that support for booting from a CD has been suppressed for Linux Servers for security reasons. This Linux WORKSTATION is on my desk at home, so I would like to be able to boot from the CD drive for such things as running a System Repair disk or test driving a Live CD. Eventually I plan also to upgrade to CentoOS 8.

What do I need to do to get a functional CD boot capability back?

Hard to say what prevented your workstation to boot from the DVDROM. The first thing you need to confirm is the boot order - is the DVD drive higher up in the order than your hard disk, and is it enabled in the first place.

You need to check the boot order in the Boot ROM, and/or the UEFI menu. How you access either depends on the computer.

It may depend on the chipset or way the optical disc drive attaches to motherboard. This would assume you in fact have a supported system, correctly chosen and burned iso and others.

The only actual CD image would be the netinstall.

The fact that the pop-up message appeared indicates to me that the system did attempt to boot from the CD/DVD drive, but was not able to do so. The message seemed to be complaining about the lack of a CD driver during the boot. The CD in the drive at the time was claimed to be bootable (it was supplied with a copy of the Linux Pro Magazine).

I think the boot order is correct. After the message about the CD driver "not found" the boot continued with the boot image on the hard drive.

Thanks for the thought.

It appears that the hardware properly found the CD/DVD drive. The complaint was that the driver was not found, not the drive itself.

Sorry, I do not understand this comment. The computer in question is a stand-alone box. I have not yet connected it to the network in my home -- I want to get the firewall properly set up first and install versions of Firefox and Thunderbird before I let the new machine take over for the one on which I am typing this response.

Thanks for trying to help -- I need all the help I can get!

Try taking a video of the display and see if you can freeze a still image of the error. The first step is to track down what level is giving the error: firmware, bootloader, ramdisk, or kernel. Any text along with that information is a bonus.