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 ...
- 1,833
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 ...
user106035
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 ...
- 2,581
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: ...
user129371
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 ...
- 610
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 ...
- 1,167
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 ...
- 317
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 ...
- 19.6k
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-...
- 10.2k
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 ...
- 2,145
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. ...
- 33.8k
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 ...
- 38.7k
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 (...
- 6,311
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). ...
- 931