A common Unix program whose primary purpose is the low-level copying and conversion of raw data.

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How to read an dar archive via LTO-6 tape

The /data folder was saved on tape with dar -R /data/ -c - | mbuffer -R 110M -P 90 -m 1G | dd of=/dev/nst0 bs=256k How can I test, list and extract it? I tried the following to test the archive ...
18
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3answers
912 views

Why does dd sometimes not wait until data is written?

Sometimes, when I write images to a flash drive, this happens: $ sudo dd if=install57.fs of=/dev/sdc 573440+0 records in 573440+0 records out 293601280 bytes (294 MB) copied, 0.549231 s, 535 MB/s ...
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0answers
23 views

How to create sector by sector image from live Windows?

I need to create image from live Windows XP, which later will be restored using linux dd command. Unfortunately I can't boot linux there to make that clone, for technical reasons. So the only way ...
2
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2answers
31 views

Using dd to write zeroes to CF card on USB Card Reader causes much reading

I am zeroing a CF card using dd dd if=/dev/zero of=/dev/sdg Watching the system using gkrellm or iostat I see lots of reads from the CF card device, followed by bursts of writes. With this ...
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0answers
24 views

USB read only with recursive filesystem

I have a USB flash drive 4GB Sandisk Edge After "DD"ing to make a live USB, the drive failed to boot and after checking it, the whole drive is broken. When using Gparted shows: | Partition | File ...
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1answer
11 views

dd over ssh poor network throughput performance

I am running a raw block copy of one ec2 instance to another ec2 instance over a local ssh connection using a large block size of 16MB. ssh -i ~/.ssh/id_rsa ubuntu@10.0.59.92 'sudo dd if=/dev/xvda1 ...
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0answers
18 views

Truncate empy space from a raw dd image

I have a raw disk image I took using dd of a Ubuntu instance. The total disk size is 300 GB, but only 5.5 GB used. Is there a way to resize the raw dd image down to 20 GB, keeping all of the 5.5 GB ...
0
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1answer
20 views

Perform dd from input file, excluding last 4 bytes of every block

I have a very large file (999,952,379,904 bytes to be precise), which is a partial disk image. Looking at it in a hex editor I have found that the structure is as follows: 0-2073 byte offsets ...
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3answers
9k views

How can I mount a disk image?

I have a disk image myimage.disk which contains the partition table and a primary partition (i.e. a FAT32 filesystem). Think that as a USB pen image. I want to mount the primary partition to a local ...
5
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1answer
3k views

Attempting to access RAM /dev/mem… says “Operation not permitted”

I am using Ubuntu 12.04 I read the following tutorial on how to access the contents of RAM in Linux.... http://www.rootninja.com/using-dd-to-search-for-strings-in-memory-or-devices/ Code: dd ...
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0answers
37 views

How come monitoring the status of a write to USB isn't reliable?

I write ISO files to USB thumb drives a lot, and I'm trying to find a way to monitor the status of a write. Googling this, I have found a bunch of solutions, including pv, dcfldd and the USR1 signal ...
0
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1answer
11 views

How do I recreate a Rasbberry pi OS from partition images?

I have a Raspberry PI that I cant take offline. Using DD I have backed up the /dev/root/ and the /dev/mmcblk0p5 boot partitions on to a windows network share. How do I restore images taken using ...
0
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2answers
42 views

zero a large block device with parallelized dd

We have a sixty terabyte block device which we want to zero using dd. Is it possible to parallelize this operation in order to reduce the amount of time it takes? I've tried running the following ...
3
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2answers
3k views

What is the difference between dd's direct and fsync options?

I would like to copy an image to a USB thumb drive. As I would like to get "real" speeds, and don't want to wait ages for the device to sync after copying the image, I would like to know which ...
2
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1answer
56 views

What's the difference between dd and cat for writing image files?

When writing image files to disk or to a USB stick, the instructions usually use dd, like this: dd if=myimage.img of=/dev/sdb How is this different from, say: cat myimage.img > /dev/sdb I ...
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0answers
14 views

Are dd read/write tests using dsync reliable under RAID?

I'm performing performance testing of some new hardware, and I was quoted from a vendor what kind of performance i should get from a dd command using the oflag=dsync option. However this amount was ...
0
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1answer
39 views

Why am i getting Very slow dd dsync test results in Linux.

I am investigating slow application issues with some New Hardware and am running into some odd results. I am trying to determine what is causing this behavior. I am using dd if=x.b1 of=x.b10 ...
2
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4answers
79 views

How To Format A Disk Image To Be Recognized By MS-DOS?

I'm trying to emulate windows with bochs on my android device. I've got the following drives: an empty disk image to install windows on, a virtual vvfat drive with the setup files, and a cdrom drive ...
2
votes
1answer
46 views

How to backup MBR with dd for Windows?

I am using dd for Windows to back up. I can back up partions on windows like this: dd if=\\.\g: of=x:\bottom_C_XP1.dd but when it comes to backing up master boot record of harddisk2 I cannot find ...
1
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1answer
23 views

Linux and DD - Infinite time to extract one file

I use dd on Linux to extract data from a tape (yeah it's really oldschool!) and I had a problem. Sometimes, when I extract a file (from different files on one tape), after a really long time and a ...
0
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1answer
63 views

How To Make A Sparse File On Android With Terminal

I'm trying to make a sparse file on android. For this I'm using Android Terminal Emulator. I have installed Busybox so I can use the dd command. Other commands like truncate aren't installed. My ...
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2answers
11k views

Rescuing a hdd with bad sectors: dd vs gddrescue

Somewhere on the internets I read that gddrescue is superior to dd at least in terms of being able to distinguish between the amount of disk reads performed on a troubled sector. Is this really the ...
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0answers
52 views

Writing image to SD card regardless of size under Windows? [closed]

I have an SD card image that contains a layout with a boot and a root partition of an existing linux system. Both partitions are located within the first 8 GB of the card and the image. The original ...
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2answers
36 views

When are bs and count settings for dd wrong?

(By wrong I mean "will break things".) Suppose we're about to use dd. We've chosen a valid set of if, of, and possibly seek and skip. We've carefully ensured that the command will not write past our ...
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2answers
43 views

Clone Drive Using Linux DD Command: Send IMG Over SSH Connection

I SSH to a VPN running Ubuntu Linux. To make backup copies of the hard drive, I use the following dd command: sudo dd if=/dev/sda1 of=/home/rick/hdImage-20150704.img It works, however, is there a ...
2
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0answers
42 views

dd an image, but only getting a fraction of the space on my SD card

I downloaded an image of Ubuntu Linaro. I then dd the image onto an SD card that is 32GB as follows: sudo dd bs=4M if=ubuntu-14.04-hdmi-z7010-20140611.img of=/dev/mmcblk0 Works fine, I can boot ...
30
votes
3answers
57k views

How do I create a 1GB random file in Linux?

I am using the bash shell and would like to pipe the out of the command openssl rand -base64 1000 to the command dd such as dd if={output of openssl} of="sample.txt bs=1G count=1. I think I can use ...
18
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5answers
30k views

How can I find what /dev my DVD-drive is?

I'm on Mac OS X, have a DVD in the DVD-drive and can look at it in the Finder. I'd like to try to create an iso of it by using the dd command. But to do that I need to know what device to use as an ...
3
votes
2answers
41 views

DD command running for over 17 hours on external 1.5TB drive

I used dd with nohup to erase a 1.5TB disk and now I can't get feedback from the progress.. Since it's been more than 17 hours I am worried... I ran the command with the disk unmounted. The disk is ...
3
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3answers
11k views

Making bootable USB flash drive with dd

I'm trying to make my 32GB flash drive bootable with archlinux. Beginning from release 2010.05, all ISO files can be directly written to USB media. So, what I've did: dd if=archlinux.iso of=/dev/sdc ...
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1answer
64 views

Is it possible to protect disk image, in format of dd, with bitlocker

I have some files on disk image. This image is in dd format. Now I want to protect that disk with bitlocker. How do I do this? I have tried mounting this image to windows with OSFMount tool, FTK ...
0
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1answer
59 views

Cloning HDD sector-by-sector (dd/ddrescue), how to skip bad blocks in the middle?

I've got a HDD with unrecoverable bad blocks. HDD is part of Raid-0 array. If I access bad blocks by any means HDD hangs. Let's assume the HDD full capacity is 500,000,000,000 bytes, bad blocks are in ...
0
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3answers
186 views

dd from /dev/zero to /dev/sda does not overwrite the whole disk

I issued dd command to zero out my hard disk. The command completed successfully but only part of the hard drive was overwritten: mint@mint ~ $ sudo dd if=/dev/zero of=/dev/sda dd: writing to ...
0
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1answer
155 views

What does dd do that pv doesn't?

I see examples online all the time of using dd in combination with pv to show progress... But, something I don't understand is that pv is perfectly capable of doing the task entirely on it's own. So, ...
25
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2answers
68k views

creating a bootable USB from command line on linux

I have a CD that's created from an ISO file which I use to install a custom version of Ubuntu via plop linux. The cd works fine but I'd like to use a bootable USB drive instead. I used the command dd ...
0
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1answer
59 views

dd writing on USB flash drive causes massive reads

I am currently restoring a usb stick with a dd image, I have previously created. However is noticed very poor write speed around ~7 MB/s although the stick is usually much faster. After looking ...
0
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1answer
42 views

Incorrect size of image file made with dd and gzip?

In the past I made a backup of a partially full partition with dd if=/dev/sda1 | gzip -5 > file.gz. Some time later, when a free space on partition was smaller I made an image file again with the ...
1
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2answers
144 views

512B to 4KiB (Advanced Format) HDD cloning with dd

What is the best practice to clone with a dd an existing 512-bytes-per-sector HDD (whole disk, not specific partitions) to a modern 4-kibibytes-per-sector Advanced Format drive? What options should be ...
2
votes
4answers
279 views

Can I copy the Macintosh HD to migrate my data to a new Mac?

I want to get a new Mac. Can I simply dd a disk image from my older mac's hdd to the new Mac with a bigger HDD (this will be further partitioned, but the old osx drive will fit within one OS X-style ...
0
votes
1answer
128 views

0M error writing file: 5 access is denied

I'm trying to write ISO on USB using dd command: dd if=evolution-64bit.iso od=\\.\f: bs=4M. I've launched cmd as Administrator, disabled my MSE anti-virus software, but it keeps telling me that Access ...
2
votes
3answers
59 views

Use dd to backup device over the network

I have a Raspberry Pi connected to the network along with a USB stick. Is it possible to use the dd command on my Raspberry Pi and automatically upload the iso to my Mac? What I mean is on my pi ...
3
votes
1answer
96 views

Head on very large files

I have 2 very big files (27G and 40G), which are output of dd command on a failing hard drive. I wanted to compare the first bytes to see if the 27G bytes is the begining/substring of the 40G. I ...
0
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1answer
240 views

How to clone a bootable SD card to a little smaller card?

I have an 8G bootable SD card used for Raspberry Pi. Currently I bought an exactly same card, in order to clone the card. I have tried the following steps: Create an image from the old card: ...
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3answers
129 views

bash script how to parse outputs

I am writing a script to test read/write performance on the network storage, but i need a bit of help to finish the script. The script is simple: reloads the nfs mount to clear the cache ...
3
votes
2answers
4k views

dd command to create bootable iso image of hard disk

Is it possible to use the dd command to create a bootable ISO image? I use the following command to do it: dd if=/dev/sda of=/mnt/sdb/my.iso I am able to create ISO, however I am not able to boot ...
3
votes
2answers
182 views

Faster recovery from a disk with bad sectors

Recently I tried to dd from an unhealthy HDD to a file. I used dd if=/dev/sdb of=somefile bs=4096 conv=noerror,sync. My problem was that dd wasted a lot of time when it encountered a bad block. In my ...
16
votes
5answers
42k views

How to create VHD disk image from a Linux live system?

Once more, I have to resort at the experts here at SuperUser, as my other sources (mainly Google ;-)) didn't prove very helpful... So basically, I would like to create a VHD image of a physical disk ...
0
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1answer
261 views

Clonezilla stopped. Can “sgdisk -z /dev/sdx” destroy all the data on sda?

I need suggestions. I wanted to backup sda2 on which Win7 is installed. I deleted the Recovery Resion. (Probably Testdisk can restore this partition because I haven't done any manipulation on that ...
0
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0answers
56 views

ddrescue failing with very large errsize (hundreds of terabytes)

I'm trying to rip a CD-ROM to an ISO file. I prefer an ISO file to a DMG or CDR file because of cross-platform compatibility. I tried using ddrescue, but no matter what options I use I get the ...
5
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1answer
18k views

What does dd conv=sync,noerror do?

So what is the case when adding conv=sync,noerror makes a difference when backing up an entire hard disk onto an image file? Is conv=sync,noerror a requirement when doing forensic stuff? If so, why is ...