dd is a traditional utility for binary data copies

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Why is fragmentation level so huge in files that contain other filesystems?

I've just found out what sparse files are and wanted to conduct some experiments on them. On wiki you can read that the files can get fragmented easily. I wanted to check how bad that is. I created a ...
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241 views

Equivalent of memmove on files: copy a range of bytes to an earlier position

What is an equivalent of memmove on files with the same input and output file, which works with large files? dd works when I move the file contents towards the right, but not if I move the contents ...
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44 views

I/O Failure when overwriting entire disk

I'm trying to write random data over a partition on my local hard disk. I'm booted into a recovery live CD (Clonezilla) and have tried the following: $ dd if=/dev/urandom bs=1024 count=4 | base64 | \ ...
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1answer
383 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), I'...
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147 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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45 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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197 views

Filesystem not showing correct size in Mac OSX

I installed a new HDD and transferred my old data to it by using dd on my old HDD and then dd again to the new HDD. However, when booting from the new HDD, it does not recognize the new, larger disk ...
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19 views

Restore unencrypted LVM2 logical volumes to LVM on LUKS setup?

I have an unencrypted Ubuntu 16.04 setup using LVM2. I'd like to 'port' this into an encrypted setup on the same computer and disk, which would save me the hassle of reinstalling all the apps and ...
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1answer
35 views

Can backups of root mounted to a logical volume be restored to a larger logical volume?

My current Ubuntu setup has root mounted to a LVM2 logical volume 'lvroot'. lvroot is 10G. I've been taking snapshots of lvroot, and then making dd backups of the snapshots (which creates a backup of ...
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44 views

Update Dell Latitude BIOS with “dd” command rather than “UNetbootin”

I'm doing these instructions. I cannot use UNetbootin, therefore I'm trying dd command instead: sudo dd if=~/Downloads/fdbasecd.iso of=/dev/sdc bs=10M After dd, the filesystem of bootable USB is ...
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22 views

Restore a disk from a snapshot in XEN 4.6

I created a snapshot with lvcreate -n snap01.vm01 -L 5G -s vg0/vm01.eclabs.de now I did some stuff on my disk i don't want to keep and want to revert it to the snapshot point. How do I restore ...
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37 views

How to recover a node/content from a tarfile that's been overwritten

Disclaimer: I'm not very good at writing questions, and mine is a very specific scenario. So I'm just going to jump straight into the situation: I was browsing my filesystem, and somehow managed to ...
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1answer
44 views

Broken disk size after incomplete dd operation

Once I was writing an ISO image into my USB disk using dd, I mistakenly pulled it out, and now it has only 10 MB of size. The correct size is 32 GB. Note that this smaller size is for the whole USB ...
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1answer
27 views

How can I check if a dd disk image is consistent (i.e. not corrupt)

I have a dd disk image. How can I check if it is consistent? (It doesn't have to be an exact copy.) I am trying to run extundelete, but I don't know if it's failing because the underlying ...
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1answer
457 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 ....
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16 views

Looking for a way to backup/mirror a drive by swapping

I want to duplicate a drive. I am unable to hook up both the old and new drive at the same time (the old powerbrick died; so I have one powerbrick to swap between two drives). In years and years ...
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33 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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79 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 ...
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111 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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66 views

Is this a correct way to back up one big drive to two smaller ones?

I have a pre-fail drive, and while I'm waiting for replacement I am trying to do full back up to two smaller drives. Given that drive is 3TG and ones I have are 1.5 and 2TB, is this a correct way to ...
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confused about dd write speed and VFS page cache

After reading some articles on the Linux VFS page cache and the tunable parameters like dirty_ratio i was under the impression that page cache would operate as both read and write caching layer. But ...
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59 views

BASH dd problem

i am trying to learn bash and now im trying to do a script for burning isos. I made the number "4" command to make sure the variables were right. the message i get when i complete my program and ...
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59 views

how to copy a piece of a text file byte-by-byte to another text file? dd, head, or?

I need to grab the first lines of a long text file for some bugfixing on a smaller file (a Python script does not digest the large text file as intended). However, for the bugfixing to make any sense, ...
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50 views

IOSTAT report doesn't match with DD benchmark

I am running a DD benchmark but the obtained results are not matching with the IOSTAT values. This is the DD sample: $ sudo dd bs=4096 count=690 if=/dev/zero of=/mnt/tmp/test oflag=dsync 690+0 ...
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24 views

Is it feasible to fill a ntfs partition/device pre install with zeroess?

In my question about copying with dd one of the commentors pointed out the method of filling the unused space with 0s. Is there a way for a dd of a 80 GB hard drive to be minimal in size? Now after ...
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98 views

Restore errors: “bad header/extent: invalid magic - magic 1701”

I'm testing these instructions to restore a backup image to an Intel Edison from a previous .img image. The backup line was: dd if=/dev/mmcblk0 of=sd/ubilinux_image.img I removed a file (to see if ...
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72 views

Write shrunken .img file to device file

I have a backup image of a device file /dev/sda3 that I created using: dd if=/dev/sda3 of=~/sda3.img. The image is very large, so I have re-sized it to remove empty space. My question is can I ...
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219 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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1k 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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203 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 what)...
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465 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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126 views

dd over smb to reformat ntfs as ext3

I've been told it's possible to use dd to reformat a portion of a Windows share drive from NTFS to ext3. I'd like to do this to be able to preserve permissions when using rsync for backups, but I ...
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43 views

For what are disk signatures being used for by GNU/Linux (distributions) / grub?

I am talking about disk signatures in context of the MBR. The area from 441 to 445 bytes. For what does the GNU/Linux kernel, GNU/Linux distributions usually use disk signatures for? I only found ...
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269 views

dd primary partition slow transfer rate

Can someone explain me why if backup ,using dd, a primary partition to a primary partition on other disk the transfer rate (MB/s) is significantly slower compared to the the rate I have if the ...
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1k 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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7 views

How to create BitDefender rescue USB drive from Elementary OS?

As the title says. I am a Linux noob and can't seem to find an app to do this. I have tried using Unetbootin and on boot I got the following error: linux.c32: not a com32r image Google tells me ...
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19 views

How do I create an bootable UBCD-stick using FreeBSD?

I have an UltimateBootCD-image-file (iso) and I want to create a bootable usb-stick from it. I tried dd'in it, % dd bs=4M if=/path/to//ubcd.iso of=/dev/da0 && sync 103+1 records in 103+1 ...
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55 views

Why does hdparm and dd show two completely different results?

I have an external hard drive (/dev/sdc1) mounted at /mount1 When running hdparm -tT /dev/sdc1 I get: /dev/sdc1: Timing cached reads: 2246 MB in 2.00 seconds = 1123.75 MB/sec Timing buffered ...
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How to image a CentoS 7 i386 ISO to a USB device?

Usually if I want to image a CentOS 7 ISO (or any Linux ISO for that matter) to a USB device, I do this via dd as follows dd if=CentOS.iso of=/dev/sdX bs=8M However I've tried this method with a ...
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56 views

ARM inforce IFC6540 not booting?

I created an image of the OS on the 64GB SD card by using dd. I did something like sudo dd if=./iforgot of=/media/usb/os/os.image I can't remember the exact stuff I wrote, but I do have the os.image ...
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48 views

dd process real vs. sys time

I have two quad core workstations. One is based on Intel Atom x86_64 architecture (WS1). Another one is based on armv7l architecture (WS2). Both are running 3.10 kernel version. Identical busybox dd ...
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Used dd on a pen drive (wrote Arch to it with Rufus) and now it's invisible

I ran dd if=/dev/zero of=/dev/sdc count=2048 on the pen drive. I can see the pen drive in the lsusb output, and dmesg says that it is 8 GB in size, but when I use, say, cfdisk, it says that there is ...
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125 views

dd speedup by async reads/writes

I was copying an SSD to an identical one today: dd if=/dev/sda of=/dev/sdb bs=4M They were connected by a SATA cable. While stracing dd I noticed that it was doing the "naive" thing: read 4M from ...
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testdisk foremost dd photorec after math help needed

Did i ask this question in the wrong place the first time? http://superuser.com/questions/957845/how-can-i-efficiently-view-validate-delete-1m-files-from-data-recovery I made such a long post about ...
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29 views

Backup full drive structure, skipping one partition content

I need to backup laptop drive. But in fact what matters is not data as in my data files kept on laptop but all systems, settings, lvm and in general whole disk structure - partitioning, UUIDs, LUKS ...
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72 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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253 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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304 views

GNU Guix usb-install freezes at GRUB after boot

I wanted to try out the GNU usb install that was released with Guix 0.7. The problem is that when I try to boot from the USB, it freezes, with the word GRUB and a flashing type line. I followed the ...
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How to restore a DD image file in my primary disk on new debian server

I have a dedicated Debian server at Online.net and I want to change the server by a more powerful (always Debian OS). For that, I have made an image on my old hard disk with this command: dd if=/dev/...
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dd does not work for an image created in freebsd 9.3

I tried to dd the image created in freebsd 9.3 $ sudo dd if=test.img of=/dev/disk2 bs=1m Password: 0+0 records in 0+0 records out 0 bytes transferred in 0.000010 secs (0 bytes/sec) This works in ...