dd is a traditional utility for binary data copies

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how to use dd to backup second linux hard drive from os x?

I have a MacBook with Linux installed on the primary hard drive. On an external USB 3.0 drive, I have OS X installed. The external drive has plenty of space so I would like to boot up OS X and make ...
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4answers
169 views

How can I convert two-valued text data to binary (bit-representation)

I have a text file with two (2) only possible characters (and maybe new lines \n). Example: ABBBAAAABBBBBABBABBBABBB (Size 24 bytes) How can I convert this to a binary file, meaning a bit ...
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40 views

osx - dd command behaving weirdly [duplicate]

I've been using dd for a couple of years now, most of the time successfully. I usually use it to dd Linux images to USB drives. My workflow doing so is as such: convert .iso image to a .img format ...
4
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1answer
38 views

How to write to an .img file with two different partitions?

I have been working on building a Linux based OS for Raspberry-pi using buildroot. I am generating the required empty .img file using "dd" and "fdisk" utilities. I am creating two empty partitions ...
4
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2answers
53 views

What is actually the speed reported by dd?

I always thought that when doing: dd if=/dev/sdx of=/dev/sdy the report which is displayed once the command finishes, such as: 79304319+0 records in 79304319+0 records out 40603811328 bytes (41 ...
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1answer
36 views

How to clone an MTPFS partition of a mounted Android phone?

Using mtpfs I've mounted a Samsung Galaxy S5 and I need to make an image of its root partition. I want to use dd or the like, but nothing seems to be able to detect/reference an MTP and/or FUSE ...
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1answer
40 views

Size difference between an iso file burnt to a cd and the file retrieved with dd

I have an iso file (foo.iso) that I burnt to a dvd with the command : growisofs -dvd-compat -Z /dev/cdrom=foo.iso I then tried the command dd if=/dev/cdrom of=foo2.iso However, foo2.iso is ...
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1answer
54 views

cant run dd command on android device

The main objective is to send a splited file to an android and join it back up with a .sh script, the file is splited to 5MB parts but its total size is unknown (trying to make an universal script), ...
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26 views

Making an ISO of MBR + X amounts of partitions

I am trying to make an ISO of a Windows Backup disc that I "burned" to my microSD card, which I did in desperation due to lack of HDD storage at the time. Now I want to get it out of there and onto ...
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1answer
36 views

Hard Disk Clone Image Size

I've created an image backup for HDDA (partition) from HostA and saved on HostB ssh -c blowfish user@ip-or-hostname "dd if=/dev/sda1 | gzip -1 -" | dd of=sda1.gz conv=sync,noerror The HDD size is ...
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1answer
80 views

dd shows a random number of records in/out [duplicate]

I'm writing some images back to block devices, with dd, and getting very strange output I've never seen before. # xz -dc goren.img.xz | dd bs=1M of=/dev/storage2/goren 35+2475166 records in ...
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27 views

Can't figure out what all these sd drives are

So I created a WindowsXP install using an NTFS drive in VMPlayer and now I want to make an image of it using dd. Here is the diskpart info from Windows: Then I use Kali as a live-cd and I find like ...
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2answers
59 views

Writing ISO file to USB

I need to write a windows7 iso file on my usb stick. I had been used to this task. I usually either use the dd tool, or unetbootin. Surprisingly both don't work today. With dd I did the following : ...
3
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1answer
39 views

How to inspect the raw contents of a partition?

I'm trying to see the contents in raw bytes of a dummy partition /dev/sda3, which I've made to be 100MiB through gparted. I want to test writing and reading on that partition. Is there a tool that ...
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5answers
324 views

How to pad a file to a desired size?

I have a file that I want to pad until it reaches 16 MiB (16777216 bytes). Currently it is 16515072 bytes. The difference is 262144 bytes. How do I pad it? This doesn't seem to be working: cp ...
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4answers
97 views

Change only one bit in a file

I have to test a hash function and I want to change only a single bit of a specific file. I tried with the dd command. That works, but I can only change a whole byte and not just a bit. sudo dd ...
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34 views

What are the [internal] steps involved in making USB drive 'bootable'?

Whenever I have to install a new Linux distro, I create a bootable USB from the distro image using some specialized program like UNetBootin. Recently, I tried to do for Fedora using 'dd' command, but ...
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1answer
58 views

Syntax When Combining dd and pv

I am a linux newbie; so, sorry if this is obvious to you... sudo dd if=/dev/sda bs=64k | pv --size 1.5t | dd of=/dev/sdb Does the block size for dd go on the left side of this after the input as ...
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236 views

USB Stick recognized but not mountable

I have a USB Stick which is recognized by my laptop but there is no partition to mount. The device is listed in /dev/ as sdb but no partition /dev/sdb1. fdisk -l also displays nothing about /dev/sdb. ...
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76 views

Overwritten superblock and dd backup files recovery

Good day, yesterday I tried to extend my swap partition ('cause suspend/hibernation didn't work) and I needed to decrease size of my debian linux disk (I don't ever remember if it was ext2/et3 or ...
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1answer
26 views

How to image certain portions of hard drive only

I have a failed hard drive which I need to extract data from. My dd kung fu is failing me right now. I know that the drive is failing at sector 60515007 to 60517093 (512b per sector), and multiple ...
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4answers
408 views

How to fill a file with a stream from /dev/urandom with a specified number of lines ?

I am trying to fill a file with a sequence of random 0 and 1s with a user-defined number of lines and number of characters per line. the first step is to get a random stream of 0 and 1s: cat ...
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1answer
66 views

How can I cross compile the dd linux tool for arm?

I need to cross-compile a full version of dd because my device only has a busybox one that doesn't support many options. Where do I get the source for it? I've been looking on the kernel repo online ...
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715 views

Why specify block size when copying devices of a finite size?

In online tutorials it is often suggested to use the following command to copy a CDROM to an iso image: $ dd if=/dev/dvd of=foobar.iso bs=2048 Why must the byte size be specified? I notice that in ...
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1answer
175 views

extract number of bytes out of a file

Is it possible to extract a few number of bytes out of a file using dd ? The file is located on a secondary drive. I apologize if this is a simple question however I'm no pro at command line.
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1answer
75 views

dd'ing SDD, decreasing write speed

My hard drive is a SanDisk SSD. The drive is new. I've booted into ArchLinux Live System, with the intention of preparing the hard drive for full disk encryption. I've noticed a significant drop of ...
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2answers
168 views

How to delete part of a binary file without copying

I need to delete the first 2 bytes of a 6MB file. However, this is an embedded Linux with only 32 Mbytes RAM and less than 1 MB free flash memory. I tried using dd, as: 1 - # dd bs=1 skip=2 ...
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Have I destroyed data on drive?

I stupidly ran the following command on an external ext4 USB disk, typing /dev/sdb instead of /dev/sda which was the new disk I was setting up: dd if=/dev/zero of=/dev/sda bs=512 count=100 These ...
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2answers
168 views

How to create a new partitioning table on SD card from the command line ? [closed]

I have tried to mount a SD card on Linux Mint, I have found the right device file and tried: mount -t vfat /dev/sdb /mnt/zauberportal ,but it failed and I tried some variations like different types of ...
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2answers
30 views

MBR and data on pendrive

I have a pendrive (/dev/sdd). I ran fdisk -l and that shows me the drive and its partitions. After that I did: dd if=/dev/zero of=/dev/sdd bs=512 count=1 I deleted the MBR (so the partitions ...
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33 views

Cloning a drive larger than your own

I made this nice backup system to turn drives into vdi's and put them on our network share. Then the next day my boss walks in with 20 new machines to replace our old ones, they have 2TB drives. How ...
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63 views

HD clone using LZ4 and DD fails

I've been cloning complete HDD images to restore OS crashes using DD and GZIP for a while now using dd if=/dev/sda | gzip > img.gz and gzip img.gz | dd of=/dev/sda This always working fine, but ...
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1answer
209 views

Why is dd so slow with a bs of 100M [closed]

I just tried to overwrite a fast ssd using dd. Using the ubuntu boot image I typed in: dd if=/dev/zero of=/dev/sda bs=100M error writing '/dev/sda': No space left on device blah blah 256 GB copied, ...
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134 views

RedHat machine will not boot when video card is removed

I "inherited" RH 6.4 on a computer with an nVidia video card. I took the image and dd'd it to another computer that has the same hardware. By design, the second computer will be headless. This ...
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2answers
405 views

dd writes to CF with delay

I have an old 64MB CF card which I use in my laptop(kernel 2.6.38) with CardBus adapter. If I write a 64MB image to this CF card, then the write speed is more than 200MB/s: T42 ~ # fdisk -lu Disk ...
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2answers
187 views

Multiple passes of wiping disk with `dd`

I want to use dd to overwrite a disk multiple times to destroy data beyond recovery. I know I could use dd if=/dev/zero/ of=/dev/sdx/ to do a pass with zeros, or dd if=/dev/null/ of=/dev/sdx/ to ...
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1answer
37 views

Can the BS option cause data inconsistency with dd?

I have a laptop partition (truecrypt) backed up with dd since it's impossible to back it up with anything else but do a raw bit by bit copy like: dd if=/dev/sda of=imagefile.img I can of course ...
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3answers
95 views

Resuming a DD of an entire disk

I'm overwriting my hard drive with random data using the good old dd: dd if=/dev/urandom of=/dev/disk/by-uuid/etc bs=512 It's a 2TB array and my MacBook (running Linux, ok?) can only write data at ...
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2answers
678 views

Why does dd from /dev/urandom stops early? [duplicate]

On my current linux system (debian jessie amd64), I am getting different behavior for dd using /dev/urandom (/dev/random behavior is properly documented). If I naively want 1G of random data: $ dd ...
3
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3answers
235 views

How to inspect the contents of /dev/sdt?

I have what I hope is not a huge problem, but could end up being a very large problem. For some context, I mistakenly ran this command on my 27'' iMac: sudo dd if=ubuntu-rescue.img of=/dev/sdt ...
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47 views

Why dd reads from output device?

While dding a CentOS 7 x86_64 DVD image to a USB drive (sdb), I monitored the progress with iostat. It kept alternating between mostly writing to the USB drive: Device: tps kB_read/s ...
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1answer
107 views

What does “dd” stand for? [duplicate]

What does dd stand for? I've always referred to it colloquially as "Disk Destroyer", but what are the "official" words that make up the acronym/command? According to this link and this link it could ...
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1answer
115 views

Delete labelled partition non interactively with one command

I know about fdisk and parted, but I was not able to figure out an non interactive way to delete a labelled partition. I imagine something like <command> <action> /dev/disk/by-label/LABEL ...
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1answer
71 views

From a sparse file to a block device

I have a system image sparse file which actual size is only a few MBs but the "apparent size" is about 1GB. I'm trying to write it to a block device efficiently (without the holes). Here are some ...
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1answer
254 views

losetup /dev/loop0 disappears after some time

at the moment I do some tests with loop devices on Linux/Ubuntu. In a small test script I have the following commands: #!/bin/sh rm testfile.x dd if=/dev/zero of=testfile.x bs=1M count=1200 losetup ...
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139 views

how to write dd command to replace backup image of root partition?

I have installed rhel6.5 in my pc. After that I have changed some configurations in file system. now I have taken backup image of /dev/sda1 which is a root partition of 15gb in size using the command ...
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3answers
178 views

How can `dd` be used to right-shift data blocks?

Consider a 100MB raw block device as a simple example. That is 204800 blocks of 512 bytes each for a total of 102760448 bytes. The challenge is to shift the first 98MB (200704 blocks) so there is a ...
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0answers
73 views

Hard Drive reporting all 1's after parted

So I have a 3TB hard drive /dev/sdc that I am trying to create a partition on. Before this point, I had the issues described below, I transfered the drive to a Windows 7 computer and created a GPT on ...
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3answers
93 views

Software RAID10 setup writes small files extremely slowly, is this normal?

I have a software RAID-10 setup on Linux 3.16.6-203.fc20.x86_64, with 1.2 metadata and the default chunk size (512K): $ cat /proc/mdstat md0 : active raid10 sdc1[4] sdb1[0] sdd1[2] sde1[3] ...
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1answer
142 views

mounting partition images made with dd

is there a way to mount and access a single partition on any mountpoint in my filesystem or must I use disk images and mount with offset? I made a partiton image with dd bs=4M if=/dev/sdb1 ...