[Solved] "Insert Guest Additions CD image..." fails

[Urpo]

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

This goes ok, no complaints.

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 6371 times

And I got the following error message:

step2error.gif (41.69 KiB) Viewed 6371 times

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

[mpack]

That usually means that the media is already mounted. You can try ejecting the existing media if you want to force a reinsertion event. Though ejection will likely give you another error, the error dialog typically offers to forcibly eject.

Not all guests have autorun enabled, so don't be surprised if no dialog pops up when you insert a CD. Just use the guest OS file manager to browse to the virtual CD drive and launch the additions installer manually. Google can tell you how, because I'm no Linux expert either.

p.s. A dithered GIF is a bit of a blast from the past! PNG tends to give better quality and better compression, and since the "Snipping Tool" is a standard app in Win7 and later hosts (including Win10) I suggest that you check it out.

[Urpo]

I tried a new how-to: "https://www.youtube.com/watch?v=HSPbwezgMno&t=9s"
It worked but the network is not working in CentOS

[mpack]

One issue per topic please. But, since you changed the subject I'm going to assume that the previous subject was solved.