apm3 DVD writer notes on command-line software
----------------------------------------------

Firstly you need to be in group 'cdrecord' to use the cdrecord and
cdrecord-prodvd software, since these require elevated priviledges to
access the writer.  Current members of this group: mike,rgm,jrl,sth
I can add more users or accounts on request.

Writing a disc will generally be done in two stages: creating the
image of the disc, and then burning it.  These can be combined using
pipelines, left as an exercise to the reader.  Note that there is an
increased chance of buffer underrun or similar problems if you decide
to do this on a loaded computer.

The image is created using the mkisofs program.  This is the latest
version on apm3 and supports a very wide range of options (see the man
page).  The version on Solaris looks a bit older but should still
work.  Usage examples:

The simplest mode of operation is to create the desired DVD directory
structure under a single directory in the filesystem, say 'dvd', eg.

apm3:/local/raid/jmi> mkdir dvd
apm3:/local/raid/jmi> cd dvd
apm3:/local/raid/jmi/dvd> 
[copy in files: everything appearing in the current directory is in
 the root directory on the DVD, etc.]
apm3:local/raid/jmi/dvd> cd ..

Then create the ISO:

mkisofs -r -J -o dvd.iso -V testdvd dvd

will create dvd.iso.  The options:

-r   Creates a filesystem with RockRidge extensions.  This allows
     UNIX-like file attributes and names on the DVD.
-J   Creates a filesystem with Joliet extensions.  These allow long
     filenames for Windows boxes (which don't understand RockRidge).
     Note that filenames here are truncated to 64 characters, but will
     still appear full-length with RockRidge.
-V   Specifies the volume ID of the disc.  You may want to specify
     this.  Solaris will use it for the name of the mount point and
     Windows/MacOS use it for the name of the disc. 

With neither -r or -J filenames are limited to 8.3 (old-fashioned DOS
filenames).  You almost certainly don't want this :)

Note that with RockRidge extensions symlinks can be created on the
disc, but only UNIX systems supporting RockRidge will see them.
RockRidge can also be specified using -R, which preserves the
ownership and file modes.  -r sets them to sensible values, which is
normally more useful since a uid/gid is probably only meaningful to
the system which wrote the DVD.

If you have root access, you can now mount the iso via loopback and
check it's contents.  Ask me for more information on doing that.

A useful variation is the -f option, which causes symlinks to be
followed while creating the filesystem.  This means you don't have to
copy the original files into your temporary directory, only ln -s
them.  Beware that apm3 does not know about the NIS map for /data, so
it can only see a limited subset of available data disks.

Once the ISO is created, a DVD can be burned using the cdrecord-prodvd
command.  Again this has a lot of options, but generally what you want
is:

cdrecord-prodvd -v speed=2 dvd.iso

to burn the DVD.  -v enables verbose output (almost certainly
desirable -- it prints progress amongst other things).  Useful extra
options:

-dummy   Goes through the complete process, but with the laser in the
         drive turned off.  For inexperienced users I *strongly*
         recommend using this the first time you burn a DVD-R disc so
         you can check the parameters of the burn, etc. and then hit
         control-C to exit without accidentally destroying a blank.
         Writes *cannot* be aborted once started!

speed=n  Placed between the -v, -dummy and other "global options" and
         the filename this allows the burn speed to be controlled.
         For DVDs this isn't terribly useful, n=1 or 2 are allowed.
         For CDs this is the "n"x rate of burning (multiple of CD
         audio playback speed) and may need to be tweaked for certain
         types of blanks.

When you execute cdrecord it prints a load of information about the
drive and disc, which may include warnings or errors if you have, for
example, made the ISO too big -- ~4.6 GB max for DVD and 650 or 700 MB
for CD depending on the size of the blank.  You then get ten seconds
to abort with control-C before it starts burning.

I mentioned CDs above, to burn those use cdrecord itself.  This hasn't
been tested on that particular drive yet though, so it would probably
be a good idea to go through an entire burn with -dummy on.  Both
these commands are (mostly) documented in the man page for cdrecord.

Finally, note that burning needs a fair amount of disk bandwidth, so
doing it over the network without testing first is not a good idea.  I
strongly recommend using the RAID /data/apm3_a (accessible from
Solaris), /local/raid on apm3 itself, for storing the ISO image.

More information, help and instructions for using -RW discs are
available on request.

--
Jonathan Irwin (jmi@ast.cam.ac.uk)