I was trying out VirtualBox on ubuntu 11.04 and I wanted to install the "Guest Additions" package in order to increase the screen size of the guest which was ubuntu 10.04.
So i got the guest os running and then clicked on Devices>Install Guest Additions (Note: the Devices Menu is on the common menu bar on the top in 11.04 and not on the window for Vbox)
A prompt asked me to download the VBoxGuestAdditions_4.0.4.iso and then another prompt asked to mount it..
Here i got an error
"Failed to open the CD/DVD image (then indicated the file path for the ISO)
Could not get Storage format of the medium (again indicated the file path of the ISO)
VERR_NOT_SUPPORTED"
I retried the process about 3 times but in vain..
Basically the iso file was not downloaded completely.. its about 36 mb and only 10 mb was downloaded before the prompt to mount came up.
The solution to this is pretty simple.Click on install guest additions again.. In the prompt copy the url that its says its goin to get the iso file from.
Download the file in the Host ie ur desktop
Shut down the guest os
Configure the guest os to use the downloaded iso file as the secondary drive.. (under Settings for the Guest in Vbox)
Start the Guest os
Now the iso file will be available under places.. Autorun..
Restart the guest and autoresize screen will now be available..
