How to properly mount a DVD-R/W drive and how to use it from
the command line?
ohartman at mail.uni-mainz.de
Thu Oct 6 05:52:13 PDT 2005
Olaf Greve wrote:
> This'll surely be a really novice question, but I'd like to get it right
> in one go, and RTFM-ing using Google somehow didn't produce uniform
> enough results for my likings. :)
> The situation: I just installed FreeBSD 5.4-Release AMD64 on my new
> machine (though the question is most likely not specific to the AMD64
> version, I guess), and upon installation time the machine had a DVD-ROM
> / CD-RW drive. Yesterday I received a new drive, being a DVD-RW drive,
> and I replaced the previous one with the new one. O.k., no problem so
> far, and the BIOS seems to properly identify the drive.
> When booting the machine, the drive is -I think- identified as "DVDW" as
> /dev/acd0, and the mountpoint it (re!)uses is /cdrom.
> Now, this is where the issue lies. When putting a CD-ROM in the drive,
> and trying to access it through the /cdrom mountpoint I get an empty
> directory listing (not correct) and when manually trying to do the
> mount /dev/acd0 /cdrom
> I get the error (on all CD-ROMs):
> mount: /dev/acd0 on /cdrom: incorrect super block
> Now, the entry in /etc/fstab for this device is set to:
> /dev/acd0 /cdrom cd9660 ro,noauto 0 0
> Which is fine for a CD-ROM drive.
> However: what should the proper settings be for a DVD-RW drive? Surely
> at least the 'ro' flag is incorrect, but is that all?
> Also: are there other locations where I should tell FBSD (and if so:
> how) about the presence of the new drive?
> Finally: I do not intent to run X on the machine, as it'll be a
> webserver only (well, incl. DB stuff etc.), and the drive is intended
> for being used to make remote back-ups on DVD-RW (yes: someone will
> physically swap the DVDs when necessary ;) ). What I'd like to know is
> what the easiest/best ways are to do so from the command-line. Does
> anyone have some scripts for this? Or perhaps some pointers to a good
> (preferrably free) program or tutorial?
> As always: thanks in advance for your time, and your answers. :)
As I can see, Uli replied the right answer, you forgot to specify the
filesystem type. but if there is a proper fstab-entry, like this:
/dev/acd0 /cdrom cd9660 ro,noauto 0 0
then it should work properly by typing
In my case, I utilize amd(8) to automatically mount a disk. This ma be
an option to you.
I also do backups on DVD+RW, but this is a more 'tricky' job if it is
done the automated way.
One possible way is to use 'growisofs' (found in
ports/sysutils/dvd+rw-tools). But this tool needs 'root' or some
workarounds when used via 'sudo' (you can not use growisofs via sudo the
Another way is to use 'burncd(8)', but it only works with dvd+rw for me
and burncd is definitely broken for some CD-R/CD-RW drives/formats
(burncd isn't capable closing the session properly, so for CD-R/CD-RW
you should use 'cdrecord' from ports/sysutils/cdrtools). For me, burncd
operates on my NEC DVD+RW drive properly, but you need ISO Images to
burn on DVD+RW/DVD+R (growisofs uses a built-in 'dd' to burn 'on the
fly', which is preferable in some ways).
An Advantage of burncd(8) is: it works with sudo(8) and it is part of
the FreeBSd OS. Disadvantage: it seems to have poor maintenance and does
not work properly with some drives. Assuming you have made a ISO image
with mkisofs (also found in ports/sysutils/cdrtools), you can burn as a
normal user via sudo via:
sudo burncd -f /dev/acd0 dvdrw /path/to/datafile
Hope this helped a little bit. There are sophisticated ways of doing
backups via DVD-+RW/DVD-+R with shell scripts, so use the search
function of the mailing lists.
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