dd is a traditional utility for binary data copies

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768 views

Can I use dd to make an ISO of a DVD that is only as large as the data on the DVD?

I am starting to make backups of my movie DVDs at home. I am using DD to make ISO images of my DVD as follows: dd if=/dev/dvd of=~/dvd/abc.iso However, even though the content of the DVD is only, ...
2
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2answers
1k views

How to use DD to clone a partition off a disk image?

I have a disk image, it's a "whole" disk image, e.g., contains multiple partitions, and I want to clone just one of them (not the first one..) onto a partition on an external drive with multiple ...
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3answers
430 views

Why does this work: “cp image.bin /dev/mapper/loop0p1”?

Why does this work? cp image.bin /dev/mapper/loop0p1 image.bin is a partition image. I have tried it and works, but why? Shouldn't a dd be used?
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4answers
2k 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 ...
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2answers
4k views

How do I resize a disk image device?

I'm trying to reduce the size of a backup drive image. Original disk had these partitions: Model: ST916082 1A (scsi) Disk /dev/sde: 160GB Sector size (logical/physical): 512B/512B Partition Table: ...
3
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2answers
163 views

How to echo output of multiple commands into md5sum?

Okay so I have a somewhat large file (~200 meg) that I need to regularly hash to see if it has changed. The catch is that there are two small fields in this file which must be ignored as they may ...
2
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1answer
559 views

fdisk, dd, and the Rapsberry pi

I was trying to wipe my 4GB SD card which acts as the hard drive for the Raspberry Pi, so I went into Mac OS X Disk Utility* and Erased the entire disk, and specified that the whole disk be one big ...
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1answer
1k views

SD Card interpreted as wrong size

I used dd to write a 2GB image to an 8GB SD card; gparted now sees it as a 2GB SD card and I can't figure out how to format it for 8GB again. ddalso sees it as a 2GB SD card when trying to format it ...
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1answer
366 views

USB key not responding when inserted

I just attempted to create a USB key for Chrome OS. I followed the instructions found here. This is what I did: 1- Downloaded a .zip version of the build. 2- Extracted the .zip file which gave me a ...
2
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1answer
1k views

Copying a working Linux instead of installing a new one [duplicate]

It is possible to move an installed Linux from one drive to another or from one disk to another by two methods: dd command which copies sector by sector including boot sector cp command, and then ...
3
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2answers
925 views

How to write file into another

I have an empty file (only zeroes are in it) of size 9,0KB and I need to write another file (with size 1,1KB) to it, but the first file must not lose its size or the rest of its contents. So if the ...
3
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1answer
141 views

reasons for a dd image of an almost-empty drive not be small after gzip

i just cleaned a 50GB partition with dd if=/dev/zero of=/dev/sda1 then added some data to it (actually installed a linux distro) some 3Gb on ext4. and decided to make a image. dd if=/dev/sda1 | ...
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2answers
486 views

How does mdraid resync work?

I have two drives in a mirror (linux sw raid/mdadm); one drive somehow left the mirror in the past and its content is now several days old. At this moment, I'm using degraded mirror (with one drive ...
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0answers
731 views

Use dd to backup disk image within an OpenVZ container

I want to use dd to backup the disk of an OpenVZ VPS in addition to traditional cold tar backups. Because I may need to migrate to a different VPS provider. From end user point of view, OpenVZ ...
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3answers
5k views

Moving /boot and MBR to a new drive

I have a CentOS 6 server with two hard drives in it. My old 3TB drive has been giving me some issues so I'm moving things over to a new drive. Because my / and /home partition are managed by a LVM ...
3
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2answers
329 views

Is it safe to only partially restore a disk image with dd?

I have saved my whole hard-disk with dd to an image file. The hard-disk contained some primary partitions formatted with ntfs, swap and ext4. I did it this way: dd if=/dev/sda | ssh user@fastmachine ...
3
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2answers
447 views

how to create ISO and hide certain files

I am a newbie here and my apologies if I am posting a question which has been answered many times in a another thread. I did my homework find some relevant information But could not. Thanks for ...
4
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1answer
111 views

Error(?) in output of the dd command

When I run the following command: dd if=/dev/sda of=output bs=512 count=1 In the middle of the output, I see this text: GRUB ^@Geom^@Hard Disk^@Read^@ Error^M What does it mean?
3
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1answer
201 views

How to enlarge existing file to specific size

I have hdd.img file, which I user as HDD for my virtual machine, but it's size is too small, how can I enlarge it? There is one method, something like: dd if=/dev/zero ds=10GB count=8 >> ...
1
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1answer
303 views

Stripping null byte blocks with a sparse file?

I've created a sparse file with dd. How do I copy contents of another file there, leaving all the zero blocks unallocated?
2
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1answer
160 views

dd is crashing after a few hours of transfer

I am trying to clone a external hardrive ( 1.5T ) to a second one ( 3T ) with dd. I am working on Unix and want to create a disk image. Here is the command I am using : dd if=/dev/disk1 ...
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1answer
206 views

How to re-size partitions in a complete hard drive image?

I have taken a complete image of a hard drive using: dd if=/dev/sda of=/home/user/harddriveimg bs=4M It would seem to me, that I should be able to re-size the partitions within it after suitably ...
2
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1answer
234 views

Using dd to cause an error in memory

The command dd if=/dev/mem of=/dev/null seek=16k bs=4k count=1 is used to test erroect injection for edac. Why? As far as I know, dd is simply copying data from those devices to somewhere else. What ...
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3answers
2k views

How can you trim files using the command line?

What is the console equivalent of the following Python code: target = file("disk", "w") # create a file target.seek(2*1024*1024*1024) # skip to 2 GB target.write("\0") target.close() Maybe some ...
1
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1answer
410 views

Read/write access on raw NTFS image

I backed up an entire 32GB NTFS partition to a raw image with with dd. The file-system on the partition in accessible under Debian after mounting with: $ sudo mount -o ro,loop ...
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2answers
738 views

Writing data on particular sectors or blocks

Not sure if it's better suited for superuser of serverfault boards, let me know. I have a drive which I repartitioned with fdisk. Initially there was only one big partition, now there are a number ...
2
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1answer
2k views

VBoxManage: Error: Can't be used as the requested device

I used the soluton from this thread but always i get VirtualBox error: The medium 'lvol.vmdk' can't be used as the requested device type (0x80004005) I've tried all controllers SATA, SCSI, IDE and ...
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3answers
1k views

Why does dd change the filesystem on the external disk?

I took out a 250 GB SATA disk from my netbook, filled it with zeroes with dd and connected it to my laptop via the usb adapter. It's correctly detected by fdisk: Disk /dev/sdb: 250.1 GB, 250059350016 ...
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2answers
704 views

Help with unzipping a .dd.gz, possibly corrupted

I recieved this file that I was told was a copy of a hard drive (or disk). The file is "sheeva-mem.dd.gz". I tried to unzip the file in a linux Fedora machine. This yielded "unexpected end of file". ...
7
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3answers
1k views

Create a Random ISO Image Using dd

I would like to create a ISO file for testing optical drives with the method mentioned here. I want to create an ISO file filled with random data, so I can burn it to a CD, read it back and compare ...
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3answers
1k views

How to clone linux installation onto an external harddisk?

I see a lot of dd related questions, but could not find answers to the following. If question/answers already exist, please point to them, then flag to close, delete or merge. Can a working linux ...
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2answers
4k views

Unpack files and directories from an image created by dd?

I created an image of an NTFS partition using dd. I wonder if I can unload/unpack the files and directories in the image to any partition whose size is larger than the image size, so that I can ...
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2answers
2k views

Check integrity of a dd backup

I just made a backup of an entire hard drive (50GB) over ssh via: dd if=/dev/hda | buffer -s 64k -S 10m | ssh myuser@myhost "cat > ~/image.img" What's now the best way to check the integrity of ...
6
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1answer
3k views

dd: writing '/dev/null': No space left on device

I am reading a 550MB file into /dev/null and I am getting dd: writing '/dev/null': No space left on device I was surprised. I thought /dev/null is a black hole where you can send as much as you ...
6
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2answers
659 views

Why did dd create a different uuid?

root@debian:/home/tiger# dd if=/dev/sda of=/dev/sdb bs=10240k 11447+1 records in 11447+1 records out 120034123776 bytes (120 GB) copied, 4729.59 s, 25.4 MB/s root@debian:/home/tiger# blkid ...
4
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3answers
536 views

from a sparse file to a block device over the network

If I have a sparse file representing a block device, then how can I efficiently restore the file over a network? Ideally, I'd use rsync -S host:file /dev/sdb, but rsync won't write to block devices. ...
4
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1answer
1k views

How do I create a USB image with a partition table?

I want to create an image of some directory tree that is writable directly to an USB drive, just like the images of many linux distributions. For example, with openSUSE you can download an ISO image ...
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3answers
2k views

dd command for windows filesystem

dd is a handy tool for backing up a whole drive or filesystem in some situations. Now I am thinking about what if I use the tool for backing up Windows file-systems / drives (Windows 2003/2008) which ...
5
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1answer
2k views

Are there alternatives for `dd`?

What other tools should I use to read and write files with truncation, seeking and skipping. dd's command line options seem inconvenient and foreign and I don't like choosing between slow, but precise ...
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2answers
5k views

Create file image container

I would like to create a 100GB file to use as a file-system. The file will be stored on an encrypted volume, so the file/file-system itself does not need to be (further) encrypted. Searching has ...
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2answers
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 ...
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3answers
1k views

How to convert dd disk image to Clonezilla?

I have disk image from VirtualBox, it is a raw image, just like dd makes it, now I would like to restore the system to real machine using Clonezilla. However Clonezilla does not recognize the image ...
2
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2answers
478 views

dd copies more data than exists in .img?

I'm trying to dd an .img file over to my micro sd (8 GB). The rom (.img) is 2.66 GB, but in my output of DD (live) it says its transfered 9 GB. I don't get how it's turning a 2 GB image into 9 GB. I'm ...
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1answer
3k views

What's faster, dd 1.5TB or rsync 500GB?

I need to save data from a failing hard drive. Sounds like ddrescue or myrescue (or maybe clonezilla?) will be my best friends here, but I'm just wondering what will likely be faster: using ...
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2answers
8k views

gzip - redirection or piping?

I will be backing up a large (750GB) disk to an external USB disk using dd. Should I be using redirection or piping? Which is more efficient? Or is there a difference? Also, what is the best block ...
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2answers
3k views

How to write a file at various offsets to a filesystem partition with dd command

Requirement I want to write a file at various offsets into the partition Partition /dev/part2 is mounted at /mypart I tried the command below: dd if=/dev/urandom of=/mypart/aaa bs=1024 seek=0 ...
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3answers
221 views

What happened to my ext3 partition

I had an ext3 partition. I ran a dd command like this: dd if=/dev/urandom of=/dev/part2 bs=1024 count=15000 seek="various values" Where various values are basically 0, 15000K, 30000K etc. The ...
4
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2answers
4k views

How to check progress when cloning a disk using `dd`? [duplicate]

Possible Duplicate: dd: How do I know if it's still working? I'm using dd to clone a disk to an image file, and compress it on the fly: dd if=/dev/sda | gzip > /mnt/image_file How ...
17
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3answers
4k 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 ...
10
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2answers
6k views

Use `dd` to cut file end part

There is probably simple trick to do this, but I can't figure from man page. How do I cut last 1MB from file with undetermined size for example, by using dd?