dd is an utility which is primarily used for low-level copying of data from storage devices.
5
votes
2answers
52 views
Linux/GParted can see partition table but dd bs=512 count=1 can't
I have an MBR formatted sd card and when connect to a Linux machine (xubuntu 12.04) it can mount a partition and parse the file system (as can GParted). However, when I try to read the MBR from the ...
2
votes
2answers
27 views
How should I format a USB prior to writing an ISO to it?
I found these Debian EeePC HowToInstallUsingStandardInstaller instructions at the Debian Wiki, stating that I can install an ISO to a USB using this:
dd if=debian-*-netinst.iso of=/dev/sdX
Do I ...
1
vote
2answers
60 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
votes
2answers
87 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 ...
0
votes
3answers
78 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?
2
votes
3answers
94 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 ...
1
vote
2answers
73 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
votes
2answers
54 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
votes
1answer
116 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 ...
0
votes
1answer
155 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 ...
-1
votes
1answer
91 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
votes
1answer
86 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
votes
2answers
147 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
votes
1answer
78 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 | ...
2
votes
2answers
112 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 ...
1
vote
0answers
185 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 ...
3
votes
3answers
302 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
votes
2answers
96 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
votes
2answers
125 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
votes
1answer
76 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
votes
1answer
96 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 >> ...
0
votes
1answer
104 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
votes
1answer
80 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 ...
8
votes
1answer
139 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
votes
1answer
94 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 ...
15
votes
3answers
450 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
vote
1answer
208 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 ...
1
vote
2answers
169 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
votes
1answer
549 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 ...
1
vote
3answers
437 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 ...
2
votes
2answers
302 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
votes
3answers
570 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 ...
2
votes
3answers
480 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 ...
5
votes
2answers
707 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 ...
0
votes
0answers
32 views
How does the “bs” option affect the dd command? [duplicate]
Possible Duplicate:
Is there a way to determine the optimal value for the bs parameter to dd?
In ...
0
votes
2answers
447 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
votes
1answer
1k 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
votes
2answers
373 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
...
3
votes
3answers
238 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
votes
1answer
497 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 ...
1
vote
3answers
467 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
votes
1answer
565 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 ...
5
votes
2answers
691 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 ...
3
votes
2answers
519 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 ...
1
vote
3answers
612 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 ...
1
vote
1answer
240 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 ...
3
votes
1answer
1k 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 ...
4
votes
2answers
2k 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 ...
0
votes
2answers
906 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 ...
0
votes
2answers
168 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 ...
