dd

Gins · 08-04-2005, 03:40 PM

I got the following from 'man' pages.

dd - convert and copy a file

What does it mean? If I want a copy a file, I will always use the 'cp' command.

What is the conversion here?

Could you give me an example so I could try?

phil.d.g · 08-04-2005, 03:51 PM

with dd you can copy anything: filesystems, CDs, hdds. for example to copy an entire cd to your hdd you can do `dd if=/dev/cdrom of=cd_image.iso`

Gins · 08-04-2005, 04:16 PM

[ka@c83-250-89-150 ka]$ dd if=/dev/cdrom of=cd_image.iso

dd: reading `/dev/cdrom': Input/output error
1121040+0 records in
1121040+0 records out

I used the command, but no avail.

I have mandrake linux 10.0 version.
In mandrake linux you don't have to mount the cdrom. It is mounted by default.
What was the problem?

By the way, what is the meaning of 'dd' ? Is it delete and destruct?

whansard · 08-04-2005, 04:26 PM

your device /dev/cdrom probably doesn't exist.
conversion is rarely used. it's for stuff like changing ascii to ebcdic. (different text formats). dd is very usedful for stuff like making a copy of a boot sector, or a floppy disk, or disk partition, and then later copying it back. dd if=/dev/fd0 of=/floppy.img would make an image of a floppy disk. dd if=/floopy.img of=/dev/fd0 would write that image file to a floppy disk in the drive.

Gins · 08-04-2005, 04:49 PM

Thanks for the reply.

What is 'dd'?

Is it delete and destruction? I can't figure out.
There should be a sensible name.

For example, man pages means 'manual pages'

Charred · 08-04-2005, 05:42 PM

I believe it's "duplicate disk," or something along those lines.

whansard · 08-05-2005, 05:21 AM

i tried to find out what 'dd' meant years ago, and couldn't really find anything. maybe 'direct data' or 'duplicate data'. just guesses.

Charred · 08-05-2005, 11:05 AM

I saw it somewhere, just can't find it again. Very frustrating. "Duplicate data" seems fairly likely, doesn't it? Either way, it's along these lines.

equinox · 08-06-2005, 05:01 AM

AFAIK "dd" stands for "disk dump" :P

Charred · 08-06-2005, 05:04 AM

Like I said, along these lines.

mramos · 09-12-2005, 10:39 AM

Can I use "dd" to copy one disk (hda), all of it, to a new one???.

Can I use this command to make a hda disk image??, executing:

dd if=/dev/hda of=<new_hd> ????

tuxdev · 09-12-2005, 10:41 AM

yes, read http://www.linuxquestions.org/questi...hreadid=362506

addy86 · 09-12-2005, 10:50 AM

Code:

$ whatis dd
dd (1)               - convert and copy a file

So it should have been cc, but since cc is reserved for the C compiler, its inventors had to rename it to dd. Simple, da?