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Questions tagged [dd]

dd is a common Unix program whose primary purpose is the low-level copying and conversion of raw data.

it will "convert and copy a file". It is used to copy a specified number of bytes or blocks, performing on-the-fly byte order conversions, as well as more esoteric EBCDIC to ASCII conversions. It can also be used to copy regions of raw device files, for example backing up the boot sector of a hard disk, or to read fixed amounts of data from special files like /dev/zero or /dev/random.

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What does the command name "dd" stand for?

I'm using dd to copy an image onto a USB. But what does dd stand for? I understand its use, but not what the name dd actually means, or is an acronym for. It doesn't even say in the man page.
john smith
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Why is the sync option used with the `dd` command?

Following instructions on this page, the page showed a dd command and a sync option at the end. The command is the following: xzcat ~/ubuntu.img.xz | sudo dd of=/dev/sdX bs=32M sync I know what is dd and how it works but I've never heard of or used…
Chinmaya B
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Can dd overwrite adjacent partitions

Would dd if=/dev/zero of=somepartition bs=512 also wipe partitions after somepartition or stop at the end of somepartition?
LogicBreaker
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Is my command to clone a drive optimal?

I have done half an hour reading around to prepare to clone my hard drive. It has multiple partitions, including a Windows partition. I am going to buy a very large external hard drive for the backup. I would like to be able to use this clone to…
Kit Johnson
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How to use the dd command to copy the content of a folder

I'm trying to use the dd command to copy the content of the folder boot0 to the my disks intial bytes. This is the command : sudo dd if=boot0/ of=/dev/sdb ibs=440 obs=440 count=1 But I get this error : dd: error reading ‘boot0/’: Is a…
Croviajo
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Can I dd a larger drive to a smaller one?

I have resized the partition of the larger drive with GParted. Can I do sudo dd if=/dev/LargerDrive of=/dev/SmallDrive ?
ChaoYang
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Does dd act at the filesystem level or go to the raw device directly?

Does dd act at the filesystem level or go to the raw device directly?
zhoucengchao
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Why must partition be unmounted before dd?

Why must partition be unmounted before using dd? For example, for copying an iso to a flash drive, we have to unmount the drive before we use dd. I've seen many places tell me to do this but never understood why?
John Robins
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dd image size - does it equal the size of the partition?

I am using dd to create an image of my boot partition on Ubuntu 14.04. This is my first time doing this. In checking the usage on my disk, I used df -h. You will see that my /dev/sda1 partition is 5.8G in size... bash$ df -h Filesystem Size …
andrewniesen
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What is the 'bs' option in dd?

I've found conflicting information on the internet on whether the bs in a command like dd bs=512 if=/home/Downloads/ubuntu.iso of=/dev/sdb stands for "bytes per second" or "block size". I couldn't find anything in the man pages, as the only…
user8292439
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Burned CD-R are not identical to the input iso image, why?

I have the issue that sometimes when I burn an iso image to a CD-R with: sudo wodim -v driveropts=burnfree -data dev=/dev/scd0 input.iso And then read it back out again with: sudo dd if=/dev/cdrom of=output.iso dd: reading `/dev/cdrom':…
Grumbel
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What is this image.dd file?

I'm running MATE 16.04 on an ASUS X550LA and have a 2.1Gb file named "image.dd" type "unknown". I tried opening it but nothing happened. Running man dd in the terminal returned Convert and copy a file What is it? Is it necessary? What effect would…
hal_v
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dd: different unit for bs, skip and count?

I am trying to copy a partition from an entire disk image. This command is working: dd if=image.iso of=test bs=512 skip=1161215 count=32768 In order to increase the speed, I'd like to set a bigger bs. dd if=image.iso of=test bs=1M skip=1161215…
None
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What is the best value for the bs option of dd command?

I am using the dd command for the first time, so I am wary, I've reading articles in wikipedia but have some unclear part, so I am asking here, is bs option matter? If I set the wrong number, would things go wrong? Like some bite in the drive be…
ChaoYang
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Create image with dd command .cow2

Using dd command, it possible to create image of type .vdi, .qcow, .qcow2, .vhd, .vhdx and .vmdk instead of .img? dd if=/dev/hda of=/path/to/desti.**qcow2 or .vhmdk** etc formats Thank you, Answers Appreciated
marvic
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