dd is a traditional utility for binary data copies

learn more… | top users | synonyms

1
vote
1answer
27 views

hexedit: change number of columns (bytes per line)

I am using hexedit to show/edit disk MBR (512 Bytes, copied with dd). When I open the file, hexedit displays the file as 9 columns, 4 bytes per column (36 bytes per line). That is very unfortunate. I ...
1
vote
1answer
18 views

What does the command pkill -USR1 -n -x dd mean exactly?

I am using dd to do a network transfer of a disk image to an sd card on my BeagleBone. Using pkill -USR1 -n -x dd in an ssh connection to this BeagleBone gives me a status update of the transfer ...
1
vote
2answers
12 views

How can I see processes being run by another instance of root on my Beaglebone

I am installing a Raspbian Linux image onto an sd card inserted into my BeagleBone Black. I will use this later in my Raspberry Pi. To do this, I am using the dd command from my MacBook Pro (via ...
3
votes
1answer
15 views

How to make dd fail if it invalid skip value is specified?

When I invoke dd with an invalid value for skip it prints an error message and does nothing, but doesn't return with a value different from 0, e.g. $ cd /tmp $ mkdir xy $ cd xy $ truncate -s 2M ...
5
votes
3answers
375 views

Why is dd not protected against writing on the active disk ?

I use dd a lot. I live in a contant fear of making a mistake one day, for example writing on sda (computer disk) instead of sdb (USB disk) and then erasing everything I have on my computer. I know dd ...
2
votes
3answers
51 views

can 'dd' be used to clone to a smaller HDD, knowing that partitions will need editing?

I've used dd to clone disks like this: dd if=/dev/sdb of=/dev/sda bs=4096 conv=notrunc,noerror,sync And it's always worked fine. Any and all docs on 'dd' take pains to remind you that the target ...
2
votes
2answers
59 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 @ ...
4
votes
2answers
57 views

why do people use “notrunc” when making an ISO from a DVD?

There are many articles on the web that describe a command-line to make an ISO image from a DVD-Video disc like this: dd if=/dev/sr0 of=mydvd.iso conv=noerror,sync,notrunc I'd like to uderstand why ...
3
votes
1answer
76 views

Differences between dd in Mac OS X and Linux

When using Linux (Debian), I often use dd to copy a disk image to an SD card. I have written a script that throws an error if the device file specified in the "of" option is too large. This keeps me ...
2
votes
2answers
103 views

dd taking weeks

A few days ago, I got the message "Windows detected a hard disk problem". I got a new hard drive, and booted into Ubuntu using a live USB. I started cloning the failing disk using sudo dd ...
4
votes
1answer
31 views

dd, seek with one block size, write with another block size

Background Info: Copying some .bin files to an SD card (to be read by an embedded device, no filesystem) Commissioning the card requires some segments to be wiped (i.e. zero'd), and others to have ...
0
votes
1answer
70 views

Is it possible to use dd to clone only the part of the hard drive which is used?

if only 1/3 of a 300GB hard disk is used. Is it possible to use dd to clone the drive (but only the 100GB that is used)? dd if=/dev/sda of=clone.img
0
votes
0answers
42 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 ...
1
vote
2answers
103 views

how to use dd to fill drive with 1's

Filling a drive with /dev/urandom seems to be very slow, so I created a file filled with FF: dd if=/dev/zero ibs=1k count=1000 | tr "\000" "\377" >ff.bin I'd like to fill the drive with copies ...
0
votes
3answers
105 views

dd write vs read performance

I have recently done some performance tests on a new server (using dd) and wonder why read performance is so much worse than write performance? Shouldn't it be another way around? file size was in ...
3
votes
0answers
35 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 ...
4
votes
1answer
234 views

Partially overwrote /dev/sda, can I recover anything?

I was messing around with my new hard drive, which only contains some personal files, and to check its write speed, I typed: sudo dd if=/dev/zero of=/dev/sda, /dev/sda/ being the new 2 TB connected to ...
10
votes
2answers
631 views

Is dd able to overwrite parts of a file?

I have a 1TB big file (disk-image from a damaged drive) and a 1.3MB small file (beginning of a disk-file). Using the contents of the small file, I want to overwrite portions of the big file. That is, ...
1
vote
1answer
68 views

How to use pv with dd?

I'm trying to use dd with pv to write an iso to a usb drive. I did: iso="myiso.iso"; dd if="$iso" bs=1M | pv --eta --size $(ls -l "$iso" | awk '{print $5}') --progress --bytes --rate --wait > ...
2
votes
2answers
168 views

dd to clone to smaller sdcard

One of my Raspberry Pi's is using a 4GB SDcard for the root/boot filesystem. As seen when mounted on another system: Disk /dev/sdc: 3904 MB, 3904897024 bytes 121 heads, 62 sectors/track, 1016 ...
1
vote
3answers
308 views

Full DD copy from hdd to hdd

UPDATE: 2 This seems a lot better than before (Thanks to Groxxda for the suggestions): sudo dd if=/dev/sdb bs=128K | pv -s 3000G | sudo dd of=/dev/sdc bs=128K ETA is about 9 hours for 3TB, whereas ...
2
votes
3answers
118 views

Why is dd running forever on a 8 GB drive

I have a filesystem handled by ZFS and it's about 8 GB. I tried to zero out the filesystem by running: dd if=/dev/zero of=/EMPTY bs=1M | true rm -f /EMPTY And normally on an ext4 filesystem, it ...
10
votes
5answers
639 views

Is it safe to take the drive image of the current working drive?

I have to backup my hard disk. I want to use dd and put the image on an external hdd. Can I do this using dd from the OS that resides on the hdd itself or do I have to boot from another device, for ...
1
vote
1answer
80 views

DD with a specific pattern

I was watching this Defcon video and around 4:30 he shows a custom pattern of drive wiping — the drive is filled with a constant text pattern. Whether he is joking or not, is this possible? How would ...
1
vote
3answers
413 views

1:1 copy with dd

I need to get a copy of an HDD that is a real 1:1, I mean not just the filesystem but also the geometry and the partition table and everything in between. if I'll just use dd if=/dev/sdb ...
1
vote
2answers
59 views

`dd` to specific location [closed]

dd is a great tool for copying and conversion. Is there any way by dd (or by any other way), to dump the first few bytes from a file to an unmounted partition? Something like this: dd if=hda2.pbr ...
2
votes
2answers
149 views

dd: 'bs', 'count' & 'seek'

I've read many guides and forum posts describing how to use dd, but one thing I've noticed is that people always use different values for the 'bs=', 'count=' and 'seek=' switches. Please can someone ...
3
votes
1answer
1k views

How to use SSH to make a dd copy of disk A from host B and save on disk B?

I want to make remote backups from disk A at will using SSH from computer B. I want to save the backups to disk B. How can I do this? I've tried using $ ssh hostname@my.ip.add.ress "sudo dd ...
1
vote
2answers
86 views

live dd over a mounted read-only root partiton

I'm trying to conceive a firmware update mechanism for a Linux-based embedded system without an additional initrd/initramfs/whatever. From within the running system which has a read-only mounted root ...
4
votes
3answers
107 views

Can I overwrite LUKS partition with it's decrypted content?

I have HDD with my data (partial backup of most important data available on other HDD), currently it's formatted as Ext4 over LVM over LUKS. I want to remove LUKS layer, but reformatting and data ...
2
votes
2answers
28 views

Backing up a partition

I am pretty new to linux. I mostly started learning after I purchased a couple of Raspberry Pis. I like to make backups of my images as I have often made the mistake of corrupting my data :). ...
3
votes
4answers
247 views

dd remove range of bytes

Given this file $ cat hello.txt hello doge world I would like to remove a range of bytes to end up with this $ cat hello.txt heorld I would like to do this with dd if possible. The reason is ...
-1
votes
2answers
66 views

How to unpack dd file on Windows? [closed]

Is it possible to unpack files created with linux dd tool on Windows? I have tried that tool http://www.chrysocome.net/dd, but it crashes under Windows 7. Any ideas?
0
votes
1answer
131 views

dd and rm -r commands

For me, the following commands do exactly the same thing: dd if=/dev/zero of=/dev/sd1 dd if=/dev/null of=/dev/sd1 rm -r /dev/sd1/* meaning, the result of their application is the same. Or least, ...
4
votes
1answer
145 views

What does this dd command do exactly?

I have the an embedded device with this SD card: [root@(none) ~]# busybox fdisk -l Disk /dev/mmcblk0: 3965 MB, 3965190144 bytes 4 heads, 16 sectors/track, 121008 cylinders Units = cylinders of 64 * ...
4
votes
1answer
156 views

Backup of a ubi file system with dd?

A have a root file system (file system - image containinf folder structure and content) on a flash drive. The flash drive uses UBI as the underlying file system file system - the way the data blocks ...
5
votes
1answer
507 views

Writing raw images safely to USB sticks

Trying lots of different linux, on all kinds of hardware I find my self typing commands like this quite often: sudo dd if=xubuntu-13.10-desktop-amd64.iso of=/dev/sdc bs=10240 Needless to say, ...
2
votes
4answers
582 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 ...
3
votes
3answers
215 views

how do I do this: dd if=coolstuff.iso of=(ssh kev@mypi )

the card reader on my laptop doesn't want to work. can I use dd (or some other tool) to write an image to a networked disk. I am trying to replace one raspberry pi distro with another. The SD card ...
6
votes
2answers
615 views

Create random data with dd and get “partial read warning”. Is the data after the warning now really random?

I create a 1TB file with random data with dd if=/dev/urandom of=file bs=1M count=1000000. Now I check with kill -SIGUSR1 <PID> the progress and get the following: 691581+0 Datensätze ein ...
11
votes
3answers
788 views

Read the middle of a large file

I have a 1 TB file. I would like to read from byte 12345678901 to byte 19876543212 and put that on standard output on a machine with 100 MB RAM. I can easily write a perl script that does this. ...
2
votes
1answer
96 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 ...
2
votes
1answer
47 views

dd command lost partition

When I used to image my USB, I used the dd command and saved that image to my Hard Disk my USB = sdb1 (4 GB) My partation = sda5 (775 GB free space) dd if=/dev/sdb1 of=/dev/sda5 operation ...
0
votes
2answers
246 views

How to write an alias function to make dd show progress bar?

According to this article, by replacing: $ dd if=/dev/sda of=/dev/sdb [additional options] with: $ pv -tpreb /dev/sda | dd of=/dev/sdb [additional options] one can augment the default dd ...
1
vote
2answers
84 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: ...
2
votes
1answer
99 views

How use tune2fs in with dd?

In this tutorial is written To regain unique UUIDs, use tune2fs /dev/sdbX -U random on every partition. Ok, but how can I use it with this command? dd if=/dev/sda of=/dev/sdb bs=4096 ...
1
vote
1answer
190 views

Why does a disk clone using dd take up more space on the target than the source image?

I'm doing some Android development on Ubuntu 11.10. I'm building a set of SD card and eMMC card Android images using a Bash script. Due to Android's idiosyncrasies, I have several file system images ...
2
votes
2answers
223 views

How to backup a running system?

I have a running Linux system, and I'd like to have a full backup of it using dd, which, in my limited knowledge is the only tool every system has. The distro doesn't matter mainly because I should ...
1
vote
0answers
34 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
1answer
1k 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. ...