I also use it to generate empty files of a given size. Or this one, to generate a random password:
dd if=/dev/random count=1 bs=12 2>/dev/null | b64encode - | \ sed -e 's/=*$//' -e '/^begin/d' -e '/^$/d'
Well indeed, and in keeping with the philosophy or do one thing and do it well.
Hence why I wonder why people like to recommend it for typical "upgrade" cloning operations, which are in most cases more than just cloning, but usually require partition resizing, possibly swapping MBR to GPT and various other wrinkles like making sure UUID/SIDs are duplicated/not duplicated depending on use case.
Indeed and GParted is my go to tool for partition management on all platforms.
Yup, that is what I was getting it. It seems to be up there with the "helpful" answers to questions that say "install linux mint", when all the questioner wanted to know how to fix a formula in Excel!
Whereas I have used dd many times to clone linux and Windows systems. If upgrading from a spinning disc to an SSD for example, I don't need any fancy bit twiddling. An exact copy is often just fine. Similarly, if I want a full backup copy then I want it to be an exact copy of everything. Other software, for example the programmes often supplied with SSDs for the purpose of cloning onto them seem to have a high probability of making a mess of the job. Probably the most obvious conclusion from all this discussion is that none of the tools is best for everyone. My preference is for fairly raw tools where I know exactly what is going on, but not everyone feels that way.
John
ny jobs then.
Why use a boring software tool to permanently erase a hard disk when there are angle grinders, club hammers and for the chemistry-literate, stuff that goes bang :-)
Or you can take it to pieces and get a couple of amazing magnets, if a bit of an odd shape.
Because the klod I'm selling the drive to might get a bit cheesed off if, when he opened the box, a load of mangled bits, iron filings, and magnet dust fell out.
Windows has Disk Management.
But it also has "diskpart.exe", which is the command line equivalent.
list disks select disk 3 clean all # Overwrites all of disk 3 with zeroes exit
It's slow because it writes the entire drive, so some number of hours must be allocated to the task. On modern drives, it will manage an average of 150MB/sec or so. And try not to erase your boot drive, which ever one it is.
You can boot a Windows installer DVD, click "Troubleshooting", select "Command Prompt", and do the diskpart sequence from there. This allows you to erase your one and only hard drive in a computer, rendering the computer... useless :-)
This is another approach for rotating hard drives.
dd if=/dev/zero of=/dev/sda # 13MB/sec dd if=/dev/zero of=/dev/sda bs=8192 # Works a lot faster, at this block size dd if=/dev/zero of=/dev/sda bs=1048576 # Additional block size, doesn't really help dd if=/dev/zero of=/dev/sda bs=221184 # A good size for older drives (IDE cable). # Older drives and their command rate are no # good with the 8192 byte block size choice.
If you set a Host Protected Area on a drive, most of the common erasure approaches don't work thoroughly. Doing a Google search on your drive model number, may give a realistic idea of the real size, and if your drive seems smaller in the tools, then an HPA could be present. An HPA could allow information to be hidden (one Dell setup, multiplexes five partitions into the primary partition table, hiding some kind of maintenance partition - a key press at startup determines whether the maintenance partition magically appears out of nowhere).
HPAs have mostly fallen out of favour, so there aren't as many tricks any more. But since we're recycling older hard drives, all sorts of weird stuff could be on there.
Paul
Klod is right for anyone who buys a used hard disk. Simply not worth it
There's always a customer for a used drive :-)
Some of those customers know what they're looking for. They would reject a WD Blue, they'd pay good money for your WD Gold. They have a list with the SMR drives in it, so they won't be buying those.
The bad customers are the people who show up on your doorstep a year later and "want their money back".
Paul
FWIW that name rings a bell! Did around 6 or so SSD upgrades on some parables we used, all a went boringly well no issues at all and all worked much faster!
Also put some SSD drives in a HP client type machine they worked very well too and now form small profile standalone machines:)
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