Trying to mount a re-writable CD to my file system Ubuntu 16.04

I am following along with "The Linux Command Line" 4th Internet addition. I am learning how to mount file systems and have been instructed to run the following commands to do so:

Code:mountIn the books example this shows the mounted devices prior to entering the CD-ROM. It is then entered again afterwards and a new entry appears:

Code:/dev/sdc on /media/live-1.0.10-8 type iso9660 (ro,noexec,nosuid,nodev,uid=500)In regards to this entry the following excerpt can be found in the book:

Quote:

At the end of the listing we see that the CD-ROM (which is device /dev/sdc on this sys- tem) has been mounted on /media/live-1.0.10-8, and is type iso9660 (a CD- ROM).

Finally these commands are given to test the mounting and unmounting of the CD:

Code:su -
umount /dev/sdc

mkdir /mnt/cdrom
mount -t iso9660 /dev/sdc /mnt/cdromI understand all of these commands but first of all when I enter my disk nautilus provides me with the message "Unable to mount Blank CD-RW Disc location already mounted" but then proceeds to seemingly mount it anyway because it shows in in the nautilus side bar and it is possible to burn files to it. mount before and after inserting the disk is unchanged however.

I determined the device is /dev/sr0 and attempted to umount it which gives the output:

Code:umount: /dev/sr0: not mountedWhen I then run the commands to mount the device file system I get the following error:

Code:mkdir /mnt/test
mount -t iso9660 /dev/sr0 /mnt/test

mount: wrong fs type, bad option, bad superblock on /dev/sr0,
missing codepage or helper program, or other errorI thought iso9660 might be incorrect but when I try it without this option I get the error:

Code:mount: /dev/sr0: can't read superblockMy /etc/fstab file has no mention of cd-rw etc only specifying sda1 and sda3 but as I understand fstab is for file systems you wish to mount at boot which I do not want for this CD

Code:# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda2 during installation
UUID=dc64aca6-b73c-4344-9974-809540739d8a / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda1 during installation
UUID=4E65-5383 /boot/efi vfat umask=0077 0 1
# swap was on /dev/sda3 during installation
UUID=4687362e-b46b-4ad4-9db0-a070b8c437c9 none swap sw 0 0I am uncertain as to the file system type on this CD-RW disk and I attempted to reformat it using the nautilus GUI to ext4 in order to get it working but I got the following error when I tried to do that:

Code:`mkfs.ext4 -F -L "" "/dev/sr0"' exited with non-zero exit status 1: mke2fs 1.42.13 (17-May-2015)
/dev/sr0 is apparently in use by the system; will not make a filesystem here!
(udisks-error-quark, 0)In conclusion I am unsure whether the disk is mounted or not given the ability to burn to it but the inability to either mount of umount using the command line. I have searched through most relevant pages which offered answers varying from modifying the kernel to fsck none of which helped so any tips would be appreciated.

this is the output of lshw -C disk and gives some details on my external DVD-RAM writer

Code: *-cdrom
description: DVD-RAM writer
product: DVD+-RW TS-L632H
vendor: TSSTcorp
physical id: 0.0.0
bus info: scsi@6:0.0.0
logical name: /dev/cdrom
logical name: /dev/cdrw
logical name: /dev/dvd
logical name: /dev/dvdrw
logical name: /dev/sr0
version: D600
capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
configuration: status=ready
*-medium
physical id: 0
logical name: /dev/cdrom