dd is a traditional utility for binary data copies

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1answer
10 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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0answers
11 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 ...
28
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5answers
23k views

Is it possible to mount a gzip compressed dd image on the fly?

I like create an image backup for the first time I'm backing up a system. After this first time I use rsync to do incremental backups. My usual image backup is as follows: Mount and zero out the ...
0
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1answer
28 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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3answers
10k views

How to dd a remote disk using SSH on local machine and save to a local disk

How can I create a backup of a remote disk using SSH on my local machine and save it to a local disk? I've tried the following: ssh hostname@my.ip.address "sudo dd if=/dev/sdX " | \ dd ...
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3answers
438 views

DD and Free Space

I have a partition (/dev/sda1) of 10 GB. Also have "dd" file of another 7 GB partition ( /dev/sdb1). When I execute the command as: dd if=sdb1.dd of=/dev/sda1 then everything goes fine but I ...
61
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7answers
10k views

dd vs cat — is dd still relevant these days?

I recently realized we can use cat as much as dd, and it's actually faster than dd I know that dd was useful in dealing with tapes where block size actually mattered in correctness, not just ...
2
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0answers
26 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 ...
3
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1answer
52 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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4answers
2k views

Why is writing SLOW on raw device, and FAST on filesystem (USB key)?

I have a USB key (PQI U822V-Speedy 32G) that I am trying to benchmark quick'n'dirty on Linux. I'm testing write bandwith. dd on raw partition I created a partition starting at sector 2048, then did ...
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2answers
44 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 : ...
0
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1answer
24 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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6answers
6k views

How do I suppress dd output?

I have a bash script that creates some file using dd. The problem is dd throws a great amount of output that is going to mess with the output of my script. Searching around I've found a solution: dd ...
4
votes
1answer
252 views

Write the same file multiple times to one file using dd

I am trying to create large dummy files on a drive using dd. I am currently doing this: #!/bin/bash writeFile(){ #$1 - destination directory/filename, $2 - source filepath $3 - blocksize, $4 - ...
3
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1answer
35 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 ...
9
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5answers
264 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 ...
1
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4answers
76 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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0answers
28 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 ...
2
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2answers
155 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 ...
3
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5answers
3k views

Fast Way to Randomize HD?

I've read about how to make hard drives secure for encryption, and one of the steps is to write random bits to the drive, in order to make the encrypted data indistinguishable from the rest of the ...
1
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0answers
135 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. ...
2
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1answer
44 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 ...
1
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1answer
59 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 ...
19
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4answers
7k views

What does dd stand for?

I know very well what the command does, but man dd, info dd tell me: 'Convert and copy a file', as does GNU Coreutils. Google says its an abbreviation of everything between medicine and bad webchat ...
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3answers
5k views

When is dd suitable for copying data? (or, when are read() and write() partial)

Short version: In what circumstances is dd safe to use for copying data, safe meaning that there is no risk of corruption due to a partial read or write? Long version — preamble: dd is often used to ...
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2answers
3k views

Copy MBR and boot partition to a smaller disk

I'm using a 32GB SD card for my raspberry pi. I have successfully transferred the operating system (Archlinux ARM) to a usb harddrive. Which means that I only need the boot partition on the SD card. ...
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0answers
55 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 ...
4
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4answers
361 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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4answers
5k views

Why does dd from /dev/random give different file sizes?

I am running the following command on an ubuntu system: dd if=/dev/random of=rand bs=1K count=2 However, every time I run it, I end up with a file of a different size. Why is this? How can I ...
6
votes
3answers
1k views

Linux/GParted can see partition table but dd bs=512 count=1 can't

I have an MBR formatted sd card and when connect to a Linux machine (xubuntu 12.04) it can mount a partition and parse the file system (as can GParted). However, when I try to read the MBR from the ...
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1answer
55 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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5answers
622 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 ...
0
votes
1answer
161 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.
1
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1answer
60 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 ...
4
votes
2answers
126 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 ...
31
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7answers
21k views

Best way to remove bytes from the start of a file?

Today I had to remove the first 1131 bytes from an 800MB mixed text / binary file, a filtered subversion dump I'm hacking for a new repository. What's the best way to do this? To start with I tried ...
3
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0answers
48 views

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 ...
4
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2answers
349 views

How to parallelize dd?

I'm currently having trouble with dd invoked with a sparse file as input (if) and a file as output (of) with conv=sparse. dd seems to be using one core of the CPU (Intel(R) Core(TM) i7-3632QM CPU @ ...
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2answers
104 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 ...
1
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2answers
26 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 ...
0
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2answers
31 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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0answers
91 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 ...
0
votes
1answer
50 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 ...
3
votes
1answer
161 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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3answers
3k views

Sending the output from 'dd' to awk/sed/grep

I'm trying to approximate the computer's write speed using dd: dd if=/dev/urandom of=/dev/null bs=1K count=10000 which gives the following output 10000+0 records in 10000+0 records out 10240000 ...
64
votes
10answers
42k views

How do I know if dd is still working?

I've not used dd all that much, but so far it's not failed me yet. Right now, I've had a dd going for over 12 hours - I'm writing an image back to the disk it came from - and I'm getting a little ...
5
votes
2answers
399 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 ...
1
vote
1answer
36 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 ...
3
votes
3answers
86 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 ...
12
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2answers
583 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 ...