[Bio-Linux] Recording CDs on Bio-Linux 3

[Tim Booth]

Dear Bio-Linux users,

Following some recent questions and suggestions, we have updated and
clarified the FAQ information regarding using the CD writer provided on
the Bio-Linux machines.  

In particular, these instructions suggest a piece of software, gcombust,
which we find particularly effective.  They also address issues with
users being prompted for a root password to access the CD recording
features.

You might also want to try out the xcdroast and gtoaster programs not
mentioned in the FAQ.  To run either of these, you will need to be in
the manager account - if you have problems with the desktop icons you
can run them directly from the command line as follows:

sudo /usr/sbin/xcdroast

and

sudo /usr/bin/gtoaster-root

respectively.

Let us know if you have any comments - we want to make CD burning as
easy as possible in Bio-Linux 4!

Regards,

Tim Booth - EGTDC

------------------

The new user FAQ entry in full:
(see http://envgen.nox.ac.uk/envgen/software/archives/000413.html)

13 - How do I make use of the CD writer? 

The default setup is that only the manager may use the CD writer. Read
on for how to change this.

Firstly, if you want to use the CD writer for backup purposes, it is
strongly recommended to make an archive of your files, and to burn this
file to a CD. Here's a suitable command to produce a compressed archive
holding 2 directories:

tar czvf archive_name.tar.gz directory1 directory2

The letters czvf mean create a zipped file, with verbose output, with
the filename "archive.tar.gz". You may also find the File Roller program
from the Accessories menu useful, as this provides a graphical
interface.

RedHat provides several CD recording programs, each with various
strengths and weaknesses. We suggest using 'gcombust'. First put all the
files you want to write to the CD into a single directory or archive
file. Then insert a blank CD, and start the program from the command
line by typing:

sudo gcombust &

Click on the "data files" tab. By clicking on the "add directory" button
you can add the directory containing your files to the list of files to
be backed up. When you have finished adding directories, click "cancel"
to close the file browser window. Clicking on "compute estimate" will
calculate the total size of the files you are about to burn to CD. 

Next, click on the "burn" tab. Select the appropriate speed for your CD
burner (32 works well on the Precision 650s), and make sure that "dummy
test run" is not ticked. Then, click on "detect SCSI drive" and "check
SCSI settings". Finally, click the "burn" button and prepare for a long
wait. When finished, a box with the message "operation completed
successfully" will appear.

To allow all users to create CDs, a simple command needs to be run by
the manager:

sudo chmod 4755 /usr/bin/cdrecord

This will take permanent effect; all users may now run the gcombust
command without the use of 'sudo'. You may want to create an icon for
gcombust on your desktop or pull-down menu, by right clicking and
selecting to make a New Launcher. 

Technical Note: The above command uses the 'setuid' feature so that the
cdrecord process will run as root. The gcombust documentation notes that
this is a potential security risk for shared machines. If you have any
concerns, please contact the helpdesk for advice.


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