I was seeing this issue today: -
Your installation CD-ROM couldn't be mounted. This probably means that the CD-ROM was not in the drive. If so you can insert it and try again.
Retry mounting the CD-ROM?
whilst trying to install a new Ubuntu 17.04 box.
I'd downloaded Ubuntu from here: -
which resulted in a 685 MB ISO image: -
-rw-r--r--@ 1 davidhay staff 718274560 8 Jun 07:12 ubuntu-17.04-server-amd64.iso
which I "ripped" to a handy USB3-capable hard drive: -
sudo dd if=/Volumes/DaveHaySSD/Software/Ubuntu/ubuntu-17.04-server-amd64.iso of=/dev/disk3 bs=1m
Password:
685+0 records in
685+0 records out
718274560 bytes transferred in 22.509606 secs (31909690 bytes/sec)
685+0 records in
685+0 records out
718274560 bytes transferred in 22.509606 secs (31909690 bytes/sec)
This AskUbuntu post: -
had the answer ( of course !! ).
For some strange reason, Ubuntu doesn't seem to like installing from a USB drive, and seems to expect a physical CD-ROM ( I know, right ? ).
The solution is to fool the installer: -
(1)Use [Alt][F2] to open a command-line ( it's BusyBox which I've seen many times before )
(2)Mount the USB disk as though it were the CD-ROM - mount /dev/sdb /cdrom
(3)Use [Alt][F1] to return to the GUI installer
(4)Choose Detect and mount CD-ROM
And off we go ….