Unable to mount blank CD/DVD - Disk is already mounted - but there's more

I suggest you use DVD Rewritable.

It's easy to burn a DVD using the command line.

growisofs -dvd-compat -Z /dev/sr0=name_of_iso

loldier us right ... I'm already using DVD+RW disks.

The second burn went uneventfully ... then I tried the first disk again, and after
considerable on-screen hysteria, Brasero blanked the part-written disk and took
that burn to the end, also successfully.

Correction: I found the excellent & clear instructions on using dconf-editor in
an askubuntu.com posting:
https://askubuntu.com/questions/89244/how-to-disable-automount-in-nautiluss-preferences

But when I put that accidentally ejected DVD+RW back in, the same error message
as I used in the title of this message appeared again, but I simply ignored it,
and Brasero continued without further incident.

George Langford

Both DVD's are readable, but neither has the boot capability built in.

I continued, establishing that its is next to impossible to create a Live DVD from
Trisquel_8. Idid find that Trisquel_7 (on the same Lenovo T420) claims that ability,
but my first try got kicked out with the following rather familiar error message:

" BraseroLibburn SCSI error condition on command 2Ah WRITE(10): [2 3A 02]
" Drive not ready. Medium not present, tray open.
" BraseroLibburn Something went wrong
" BraseroLibburn called brasero_job_error
" BraseroLibburn finished with an error
" BraseroLibburn asked to stop because of an error
" error = 15
" message = "An error occurred while writing to disc"
" BraseroGenisoimage stopping
" BraseroGenisoimage got killed
" BraseroGenisoimage disconnecting BraseroGenisoimage from BraseroChecksumImage
" BraseroChecksumImage stopping
" BraseroChecksumImage disconnecting BraseroChecksumImage from BraseroLibburn
" BraseroChecksumImage closing connection for BraseroChecksumImage
" BraseroLibburn stopping
" BraseroLibburn closing connection for BraseroLibburn
" Session error : An error occurred while writing to disc
" (brasero_burn_record brasero-burn.c:2856)

A glance at this third DVD+RW showed about the same ten percent progress
as with the second DVD above.

I continued, trying "again" to create a bootable DVD ... this time it would
not mount the disk because "an operation is pending" ... but then I found that
the operation window was frozen, and that a lot of HDD and DVD activity was
going on. When I put that window in the tray and then reopened it, the window
was blank, and the disk activity continued ... while I sat, terrorized that
all this was erasing and rewriting my HDD. After about five minutes, another
small window popped up, saying "unable to mount disk"

Ejecting and examining the disk, it is visually indistinguishable from the first
two DVD's burned from the .iso file, but not from the Startup Disk Creator menu.

I just tried to open that disk from the Desktop ikon, and now its activity light
is blinking steadily, as though it is continuing with some invisible process ...
The first two DVD's took about fifteen minutes to be completed, so maybe now this
disk will be bootable ...

Nope. It's just another .iso image, as though the burn process got hijacked by
Brasero. I had looked at the DVD after the intermediate stage of this burn when
it was visually indistinguishable from the first two .iso images on their DVD's
and this DVD has had what once was a data disk with actual files (including one
file called Boot) now is just one big 2.6GB .iso file.

I'll try again, using Trisquel_7 and the Startup Disk Creator, hoping that the
frequent drawer-opening phenomenon won't occur ...

When I placed the fourth DVD in the drive and started Startup Disk Creator, the
CD burner drive light started blinking and continued for several minutes with no
outward indication of any feedback. In the end, it looks just like the first
three DVD's to my eye, but the Startup Disk Creator box appeared, listing two
DVD's, each with 4.4 GB of space consumed, and insufficient disk space to go on.

Opening this fourth DVD was impossible, as "Properties" shows that the contents
are "nothing." The third DVD, which once showed the 2.6GB .iso file, now comes
up with File Manager as a "Blank DVD." These last two DVD's are visually
indistinguishable from the first two DVD's which do still show up as real .iso's.

That's where it stands ...

George Langford

Is https://trisquel.info/en/wiki/burn-trisquel-cd-images outdated? It simply says "right click an .iso image and select Write to Disc...". In GNOME Shell (at least), there is that entry.

That said, the "SCSI error" suggests a defective DVD drive...

Facing an uphill battle with my attempts to create a bootable DVD version
of Trisquel_8, I gave up this effort and started another thread regarding
the problems I face trying to repair the malignant desktop ...

George Langford