dd is a traditional utility for binary data copies

learn more… | top users | synonyms

2
votes
4answers
1k 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 ...
2
votes
2answers
2k 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. ...
1
vote
2answers
121 views

dd command: Finding read/write throughput of a flash/SD?

I am running petalinux from sd card. And trying to find data copying rate from Sd card and from QSPI flash that is there on the Xilinx Zynq board. As suggested here , I am doing like this: ...
1
vote
2answers
134 views

Debian: Create compressed Harddrive for copy

On my Debian system I have a box with certain configuration settings that I like but I've had to change them continuously. There have been times that I've gotten into a some-what irreversible ...
0
votes
2answers
29 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 ...
3
votes
1answer
135 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 ...
1
vote
1answer
19 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 ...
1
vote
1answer
29 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 ...
1
vote
1answer
148 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 ...
-1
votes
1answer
378 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 ...
3
votes
0answers
34 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 ...
3
votes
0answers
51 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 ...
3
votes
0answers
146 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
votes
0answers
42 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 ...
1
vote
0answers
51 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 ...
1
vote
0answers
32 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 ...
1
vote
0answers
47 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 ...
1
vote
0answers
36 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 ...
1
vote
0answers
187 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 ...
1
vote
0answers
778 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 ...
0
votes
0answers
36 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 ...
0
votes
0answers
73 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 ...
0
votes
0answers
119 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 ...
0
votes
0answers
754 views

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 ...