Editing Dd (Unix) (section)

=== Data transfer ===
The command can duplicate data across files, devices, partitions and volumes, and it can transform data during transfer as specified via option {{code|conv}}. In some cases, data transfer is faster with {{code|cat}}.<ref name="relevant" />

To create an [[ISO image|ISO]] [[disk image]] from a [[compact disc|CD-ROM]], [[DVD]] or [[Blu-ray]] disc:<ref>{{cite web | url=https://wiki.archlinux.org/title/Optical_disc_drive#Creating_an_ISO_image_from_a_CD,_DVD,_or_BD | title=Creating an ISO image from a CD, DVD, or BD | work=ArchWiki | accessdate=April 18, 2022 | archive-date=April 18, 2022 | archive-url=https://web.archive.org/web/20220418171303/https://wiki.archlinux.org/title/Optical_disc_drive#Creating_an_ISO_image_from_a_CD,_DVD,_or_BD | url-status=live }}</ref>

<syntaxhighlight lang="bash">
blocks=$(isosize -d 2048 /dev/sr0)
dd if=/dev/sr0 of=isoimage.iso bs=2048 count=$blocks status=progress
</syntaxhighlight>

To restore a drive from an image file:

<syntaxhighlight lang="bash">
dd if=system.img of=/dev/sdc bs=64M conv=noerror
</syntaxhighlight>

To create an image of partition sdb2, using a 64 MiB block size:

<syntaxhighlight lang="bash">
dd if=/dev/sdb2 of=partition.image bs=64M conv=noerror
</syntaxhighlight>

To [[Disk cloning|clone]] one [[Disk partitioning|partition]] to another:

<syntaxhighlight lang="bash">
dd if=/dev/sda2 of=/dev/sdb2 bs=64M conv=noerror
</syntaxhighlight>

To clone drive ad0 to ad1; ignoring any errors:

<syntaxhighlight lang="bash">
dd if=/dev/ad0 of=/dev/ad1 bs=64M conv=noerror
</syntaxhighlight>