2. Procedure

Summary of Steps

Create a large partition to hold the CD Image Files.
Copy the CD to an image file using the "dd" command.
Mount the CD image file within the directory tree.
Share the directory on the network using Samba, NFS, etc.

2.1. Creating the ISO Images

Choose (or create) a file system with the largest available disk space on it. Keep in mind that CD-ROM's can hold around 640MB of data, so if you want to share 8 full CD's on your network, you'll need 5.1GB of space available.

Login as root or "su" to root.

bash# df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/hda5             1.4G   82M  1.3G   6% /
/dev/hda1              15M  827k   14M   6% /boot
/dev/hda7             2.4G 1008M  1.3G  43% /usr
/dev/hda8            23.6G 11.7G 11.7G  50% /home

Here the /home filesystem has the most available space, so it is the most suitable filesystem to use for dumping the CD images to.

 
bash# cd /home
bash# mkdir image
bash# cd image

Now, copy the CD to an iso image. You must know the device name of your CD-ROM drive (usually /dev/cdrom, it could be /dev/scd0 for SCSI CD-ROM's) I'll use the Mandrake distribution CD-ROM as an Example:

bash# dd if=/dev/cdrom of=mndrk71.iso

The "if=" is the input file, the "of=" is the output file. You should see a message stating the number of records in and number of records out (hopefully with no i/o errors).

2.2. Mounting the ISO Images

The next step is to mount the iso image file. Let's create a directory under /mnt to place the mounted file.

bash# cd /mnt
bash# mkdir iso
bash# cd iso
bash# mkdir mndrk71

Now mount the ISO image file to this newly created directory

bash# mount -o loop -t iso9660 -r /home/image/mndrk71.iso /mnt/iso/mndrk71

The "-o loop" means use the option that mounts a file as a block device. The "-t iso9660" means that the file is in the iso9660 CD-ROM format. The "-r" means to mount read-only.

Now you can:

bash# cd mndrk71
bash# ls -al

You should see a listing (ls) of the files and directories that are on the actual CD (only now they're inside the iso image file, and that's what you're currently looking at!)

2.3. Mounting the Image upon System Restart

Now that we've manually mounted the image, and made sure it works, an entry needs to made in the /etc/fstab file so that the image is remounted on the next system startup. It's important to make the entry AFTER the entry for the parent filesystem, e.g. /home (I use vim, but Emacs, Joe, Pico or Jed will work just as well):

bash# vim /etc/fstab

After the line that looks like the following (or whichever filesystem you've placed your images):

/dev/hda8 /home ext2 defaults 1 2

Insert the following line with your text editor:

/home/image/mndrk71.iso /mnt/iso/mndrk71 iso9660 ro,loop,auto 0 0

2.4. Sharing it on a Windows Network using Samba

You'll need to have Samba installed and working to perform the next steps (that's outside the scope of this instruction). If it's not yet installed, consult your Linux distribution's instructions for installing the Samba package. Or you can visit the Samba website at http://us1.samba.org/samba/samba.html for installation instructions, binaries, and/or the source code.

To share your mounted CD's on a windows network, simply create a stanza in the /etc/smb.conf file similar to the following:

[cdimages]
  comment = All Shared CD Images
  path = /mnt/iso
  public = yes
  writable = no

This will share all the subdirectories under the /mnt/iso directory on the network. To mount the share to a local drive (in this case the I: drive), bring up an MS-DOS Prompt on the Windows machine and type the following:

C:\> net use I: \\yourlinuxmachine\cdimages

Each CD image will now appear as a subdirectory on the I: drive of your Windows machine.

To mount ONLY the Mandrake CD image to a drive letter (we'll use M:, the root drive of which, will correspond exactly to the CD as if it was just inserted in the CD-ROM drive), create the following stanza in the /etc/smb.conf file.

[mndrk71]
  comment = Mandrake Linux 7.1
  path = /mnt/iso/mndrk71
  public = yes
  writable = no

Then, at your MS-DOS Prompt, mount it with the following command:

C:\> net use m: \\yourlinuxmachine\mndrk71

Note:: The Samba smb.conf file stanzas presented here are simplified, and not entirely secure. Many more options exist for a Samba share which limit who can mount the shares, control how user authentication is performed, whether the share is even browseable through Network Neighborhood on the Windows machines.

2.5. Sharing the Images on a Unix network using NFS

Make sure that NFS is running and configured correctly on your Linux machine, then add the following to the /etc/exports file using your own preferred options:

# sample /etc/exports file
       /mnt/iso            (ro,insecure,all_squash)

Now, when typing "showmount -e yourlinuxmachine" you should see that the /mnt/iso is included in the exports list.