Reading CDs

This document describes some of the ways to read CD/DVDs on the departmental Linux machines (running Scientific Linux 5), and also how to eject them.

Using GNOME

Under Gnome the default desktop, once you've put the CDrom into the drive an icon will appear on the desktop. Double click on the icon, (or right click and select open) to view the contents.

To eject the CD: from the content viewer under the File menu select Eject or right click on the CD desktop icon and select Eject.

Using the command line

Using the command line (in a terminal or xterm window for example) look under /media/ In that directory you will find your device, and possibly the names of others which were mounted at a different time. Change directory into the right directory and you'll see all the files.

The old syntax of /opt/med/cd can also be used.

to list the files on your cdrom type:

  ls /opt/med/cd/

to cd to your cdrom use:

  cd /opt/med/cd/

and to look at a file on your cdrom:

  more /opt/med/cd/filename

If the CD is blank, then as there is no file system on the CD, the error message

  /opt/med/cd: Input/Output error

is returned when attempting to access /opt/med/cd paths. If you wish to see if there is a CD in the drive some drives have green lights which come on when the CD is in the drive and go out when you remove it.

To eject the CD make sure you are not using the CD ie not using the directory or any files from /opt/med/cd and run:

  amq -u /opt/med/cd

then the eject button (or eject command) should work.

Mixing the graphical and command line methods

If you use the command line method to view the contents of the CD, you will not be able to use the Gnome graphical interface to eject the CD. You must use the command line interface way described above to eject the CD in this case.

What file-system types are supported?

All machines should support IS-9660 CDs, with or without Rock-Ridge extentions (which permit long case-sensitive names and unix-permissions). Newer machines will support UDF format (as used on DVDs). Systems also support their native file-system types as well (e.g. ext2 or ext3 on Linux) but these are rare on CDs. The system will automatically determine the type of the CD (if it can) and mount it.

Sometimes a CD or DVD will contain several different file systems possibly for different kinds of system, e.g. MacOSX files and Windows files etc. Mechanisms for accessing these are available but beyond the scope of this document.