4.3. CD-Rs and CD-RWs

4.3.2.1. Using X-CD-Roast to Duplicate CD-ROMs

To duplicate an existing CD-ROM for backup purposes, click the Duplicate CD button in the main panel. You can read all of the tracks on a CD — all CD-ROM information, including data and audio, is stored on tracks — by clicking Read CD. You can set the speed at which you read a CD-ROM as well as find out some information about the CD-ROM track such as its type and size. If you are copying tracks from an audio CD, you can preview each track with Play Audio-Tracks. Since X-CD-Roast reads all tracks of a CD-ROM by default, you can delete unwanted tracks with Delete Tracks.

Finally, to burn your tracks onto CD-R(W) media, choose Write CD. Figure 4-9 shows the Write CD dialog box, where you can configure the speed at which you read and write the tracks to CD-R(W), as well as whether you wish to copy the CD-ROM on-the-fly or create an image file first before burning (which is recommended to prevent write or read errors from occurring during the duplication process). Click the Write CD button to start the burning process.

4.3.2.2. Using X-CD-Roast to Create a CD

It is always recommended to backup personal data and information often in case of hardware failure or file system corruption. X-CD-Roast allows you to backup files on your hard drive partition using Create CD. This facility allows you to add files and directories into a CD session using Master Tracks. There are other options within the Master Tracks dialog that allows you to configure advanced settings; however, the defaults are set correctly to create data CD-ROMs, so no further configuration is necessary. Figure 4-10 shows a session that is preparing the entire /home directory for backup.

Highlight the files and directories that you wish to add to the session and click Add. After you have added all files and directories you want to write to the CD-R(W), click the Create session/image tab to create the .img file. You must first click Calculate size, then click Master to image file to create the image.

To write your tracks to the CD-R(W), click Write Tracks from the panel on the left. In the Layout Tracks tab, highlight the image file you created in the box on the right, and click Add. The image displays in the Tracks to write box on the left side. Click Accept track layout, and click the Write Tracks tab to return to the main writing dialog. Click Write tracks to write the image to the CD-R(W).

	Tip
	You can also create and write the image to the CD-R(W) in one step by clicking Master and write on-the-fly in the Create session image tab. This saves a few steps but can sometimes cause read-write errors. It is recommended that you use the multi-step method instead of the on-the-fly methods.

4.3.2.3. Writing ISOs with X-CD-Roast

Large files that end in .iso are known as ISO9660 (or ISO) image files. For example, Red Hat Linux is freely available as ISO images that you can download and write to the CD-R(W). There are also other ISO image files available on FTP and websites. There are other file types that can be burned as images, such as .img and .raw, but ISO images are the most common CD image format.

To write an ISO image file to a CD-R(W) with X-CD-Roast, move the ISO file to the path specified during setup, then click Create CD. In the Layout tracks tab, highlight the ISO image file you wish to burn and click Add, then Accept track layout. This automatically loads the Write Tracks tab, where you can click Write Tracks to burn the image to the CD-R(W).

4.3.3.1. Using mkisofs

The mkisofs utility creates ISO9660 image files that can be written to a CD-R(W). The images created by mkisofs can include all types of files. It is most useful for archival and file backup purposes.

Suppose you wish to backup a directory called /home/joeuser/, but exclude the subdirectory /home/joeuser/junk/ because it contains unnecessary files. You want to create an ISO image called backup.iso and write it to CD-R(W) so that you can use it on your Red Hat Linux PC at work and your Windows laptop for trips. This can be done with mkisofs by running the following command:

mkisofs -o backup.iso -x /home/joeuser/junk/ -J -R -A -V -v /home/joeuser/

The image is created in the same directory that you ran the command. Table 4-1 explains each command line option. For more information on using mkisofs, refer to the additional resources in Section 4.4 Additional Resources.

You can now use the ISO image file with either X-CD-Roast as described in Section 4.3.2.3 Writing ISOs with X-CD-Roast, or using cdrecord, the command line based CD recording utility. For more information about using cdrecord, refer to Section 4.3.3.2 Using cdrecord.

4.3.3.2. Using cdrecord

The cdrecord utility writes audio, data, and mixed-mode (a combination of audio, video, and/or data) CD-ROMs using options to configure several aspects of the write process, including speed, device, and data settings.

To use cdrecord, you must first establish the device address of your CD-R(W) device by running the following command as root at a shell prompt:

cdrecord -scanbus

This command shows all CD-R(W) devices on your computer. It is important to remember the device address of the device used to write your CD. The following is an example output from running cdrecord -scanbus.

Cdrecord 1.8 (i686-pc-linux-gnu) Copyright (C) 1995-2000 Jorg Schilling
Using libscg version 'schily-0.1'
scsibus0:
	0,0,0     0) *
	0,1,0     1) *
	0,2,0     2) *
	0,3,0     3) 'HP      ' 'CD-Writer+ 9200 ' '1.0c' Removable CD-ROM
	0,4,0     4) *
	0,5,0     5) *
	0,6,0     6) *
	0,7,0     7) *

To write the backup file image created with mkisofs in the previous section, switch to the root user and type the following at a shell prompt:

cdrecord -v -eject speed=4 dev=0,3,0 backup.iso

The command sets the write speed (4), the device address (0,3,0), and sets write output (verbose [-v]), which is useful for tracking the status of the write process. The -eject argument ejects the CD-ROM after the write process is complete. The same command can also be used for burning ISO image files downloaded from the Internet, such as Red Hat Linux ISO images.

You can use cdrecord to blank CD-RW discs for reuse by typing the following:

cdrecord --dev=0,3,0 --blank=fast