Linked Questions
55 questions linked to/from Is there a way to determine the optimal value for the bs parameter to dd?
161
votes
9
answers
50k
views
dd vs cat -- is dd still relevant these days?
I recently realized we can use cat as much as dd, and it's actually faster than dd
I know that dd was useful in dealing with tapes where block size actually mattered in correctness, not just ...
33
votes
12
answers
21k
views
Erasing a Linux laptop
I have a laptop with Debian on it, and I am going to sell this laptop.
Would it suffice to erase the Debian installation before selling it to completely clean up my laptop from my personal data, and ...
45
votes
5
answers
152k
views
Full DD copy from hdd to hdd
ORIGINAL QUESTION:
If I have 2 identical hard drives with the following characteristics:
SATA 6.0 Gb/s
5400 rpm
3TB
How long should a full dd copy take to complete?
So far it's been running for 5 ...
60
votes
3
answers
55k
views
Is it better to use cat, dd, pv or another procedure to copy a CD/DVD?
Background
I'm copying some data CDs/DVDs to ISO files to use them later without the need of them in the drive.
I'm looking on the Net for procedures and I found a lot:
Use of cat to copy a medium: ...
31
votes
4
answers
53k
views
Why dd takes too long?
I need to copy one disk to another. I tried with the command below and it takes nearly a day to copy 1 TB of disk in federo.
dd if=/dev/sda of=/dev/sdb
I have tried the same on a Unix(HP-UX) system ...
40
votes
4
answers
36k
views
Why does dd from /dev/random give different file sizes?
I am running the following command on an ubuntu system:
dd if=/dev/random of=rand bs=1K count=2
However, every time I run it, I end up with a file of a different size. Why is this? How can I ...
20
votes
4
answers
8k
views
Got "No space left on device" when cloning 1TB disk to 1.2TB disk using dd
I am trying to using the following dd command to clone remote xfs disk to another location.
ssh root@source_ip "dd if=/dev/vda2 bs=16M conv=noerror,sync status=progress " | sudo dd of=/dev/nvme1n1 ...
84
votes
2
answers
21k
views
When is dd suitable for copying data? (or, when are read() and write() partial)
Short version: In what circumstances is dd safe to use for copying data, safe meaning that there is no risk of corruption due to a partial read or write?
Long version — preamble: dd is often used to ...
22
votes
5
answers
14k
views
Does dd do any kind of verification?
I'm using dd to copy data from an old hard drive to a new one. I want to be sure that the data's integrity is secure.
On this answer, Gilles says
If [dd] terminated successfully, then the backup ...
31
votes
3
answers
30k
views
How to unzip and dd a disk image to an SD Card with a single command?
I am under the following restrictions:
I have a 1.0 GB .zip file on my computer which contains one file, a disk image of raspbian. When uncompressed, this file is 3.2 GB large and named 2015-11-21-...
22
votes
6
answers
59k
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 ...
21
votes
4
answers
17k
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. ...
13
votes
5
answers
13k
views
Resuming a DD of an entire disk
I'm overwriting my hard drive with random data using the good old dd:
dd if=/dev/urandom of=/dev/disk/by-uuid/etc bs=512
It's a 2TB array and my MacBook (running Linux, ok?) can only write data at ...
12
votes
5
answers
30k
views
How can I clone/backup/restore Windows 10 from Linux?
Case scenario:
$ sudo fdisk -l
Disk /dev/sda: 223,6 GiB, 240057409536 bytes, 468862128 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (...
8
votes
3
answers
10k
views
Does dd copy everything, including all metadata and all "empty" blocks
Suddenly something was messed up with my partitions, or just one partition. I have a default Ubuntu installation, on a Kingston SSD, with the root file system encrypted with LUKS, (using AES I think). ...