Unable to insert the virtual optical disk ...\VBoxGuestAdditions.iso into the machine CentOS-8

[jvmakela2]

Platform:

- VirtualBox 6.0
- host: Windows 10
- guest: CentOS 8

I want to increase the display resolution of the guest and window size. I've got two monitors (both 1920x1080)
and would like to run VM on the other screen and Windows on the other.
I got instructions on page:

https://linuxconfig.org/virtualbox-inst ... n-redhat-8

and I've done step 1: Install all packages required for VirtualBox guest addition compilation. Open the terminal window and execute the following command:

# dnf install tar bzip2 kernel-devel-$(uname -r) kernel-headers perl gcc make elfutils-libelf-devel

step1.png (239 KiB) Viewed 5404 times

Step 2: Insert Virtualbox guest additions ISO image
I downloaded the latest version of VB guest additions ISO image: https://www.virtualbox.org/wiki/Testbuilds
and replaced the existing ISO with the latest ISO (renamed it in C:Program Files\Oracle\VirtualBox\VBoxGuestAdditions.iso"

step2.gif (50.98 KiB) Viewed 5404 times

And I got the following error message:

step2error.gif (41.69 KiB) Viewed 5404 times

And I've got no clue what to do next?
Just a novice with Linux.

[hunter86_bg]

What is your VirtualBox version?

Usually lack of Vbox guest tools is not critical for your CentOS8 system.

[TrevorH]

I'm going to guess that the drive already has a "CD" inserted in it and it's mounted so that when you try to insert a new one, it tries to eject it and fails because it's in use... In which case, umount it first then eject it and then try inserting new media.

[nouvo09]

I'm going to guess that the drive already has a "CD" inserted in it and it's mounted so that when you try to insert a new one, it tries to eject it and fails because it's in use... In which case, umount it first then eject it and then try inserting new media.

+1 except it is not mounted and clicking on "insert" does mount it.