Archives For November 30, 1999

This simple and brief tutorial will show you how to backup live CD or DVD to iso image on Ubuntu Linux using dd command.

dd is a command on Unix and Unix-like operating systems whose primary purpose is to convert and copy a file. On Unix, device drivers for hardware (such as hard disks) and special device files (such as /dev/zero and /dev/random) appear in the file system just like normal files; dd can also read from (and in some cases write to) these files. As a result, dd can be used for tasks such as backing up the boot sector of a hard drive, and obtaining fixed amount of random data.

To make iso image out of CD or DVD:

Insert your live CD or DVD into computer, then you can check the device name by running below command:

df -lh

You’ll get a similar output. The last line tells the device name /dev/sr0 and mount point /media/handbook/CD-Rom

Filesystem Size Used Avail Use% Mounted on
/dev/sda6 92G 47G 41G 54% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
udev 870M 4.0K 870M 1% /dev
tmpfs 176M 980K 175M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 878M 3.5M 874M 1% /run/shm
none 100M 56K 100M 1% /run/user
/dev/sr0 807M 807M 0 100% /media/handbook/CD-Rom

Now, use below command to create iso from it:

dd if=/dev/sr0 of=~/backup.iso bs=1000000 count=512 &&sync

Here if reads from file /dev/sr0, of write to file backup.iso, ~/ means user home directory. The value of ‘bs’ means read and write up to 1000000 bytes at a time.

For more, run:

man dd