Tonic for your Backup Woes: CD Backups In Linux (Part One) - Page 3

Burning a disk is a two-step process. First create an ISO9660 image, then burn the image to disk. mkisofs creates filesystems, while cdrecord controls the actual writing to disk.

$ mkisofs -o monday_backup.iso -JRVv /home/carla/

-o specifies the backup filename
-J use Joliet naming records, for Windows compatibility
-R Rock Ridge naming conventions for preserving filename length and cases, for UNIX/Linux
-V Volume ID- this is the disk name that shows up in Windows Explorer
-v verbose, for a running commentary as the image is created

Test The Image

Mount the image to verify everything is OK and to lessen the risk of creating a coaster:

# mount -t iso9660 -o ro,loop=/dev/loop0 monday_backup.iso /cdrom

This mounts it in the /cdrom directory, and if the image is error-free, all the files and directories you selected should appear.

Now that you have a nice ISO image, find the SCSI device address of your CD writer, as root:

# cdrecord -scanbus
Cdrecord 1.10 (i686-pc-linux-gnu) Copyright (C) 1995-2001 Jvrg Schilling
Linux sg driver version: 3.1.24
Using libscg version 'schily-0.5'
scsibus0:
0,0,0 0) 'TOSHIBA ' 'DVD-ROM SD-M1202' '1020' Removable CD-ROM
0,1,0 1) 'LITE-ON ' 'LTR-24102B ' '5S54' Removable CD-ROM
0,2,0 2) *
0,3,0 3) *
0,4,0 4) *
0,5,0 5) *
0,6,0 6) *
0,7,0 7) *

Burn, Baby

# cdrecord -v -eject speed=8 dev=0,1,0 monday_backup.iso

-v verbose
-eject eject when finished
-speed write speed
-dev device number from cdrecord -scanbus
And finally, enter the name of the image being burned.

To perform a quick erase on a CD-RW, which erases only the Table of Contents (TOC) and the Program Memory Area (PMA), type:

# cdrecord --dev=0,1,0 --blank=fast

To completely erase a disk, type:

# cdrecord --dev=0,1,0 --blank=all

Next week we'll dig more deeply into command options, automating CD backups, and restoring data from a CD.

Resources

Linux 2.4 SCSI subsystem HOWTO
CD Writing Howto

» See All Articles by Columnist Carla Shroder