Can I wipe a hard drive using a puppy linux live CD?

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average novice user
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Can I wipe a hard drive using a puppy linux live CD?

#1 Post by average novice user »

Can I wipe a hard drive using a puppy linux live CD?

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rcrsn51
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#2 Post by rcrsn51 »

Code: Select all

dd if=/dev/zero of=/dev/sda

average novice user
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Much thanks

#3 Post by average novice user »

Much thanks

alice
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#4 Post by alice »

what's the meaning?

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GustavoYz
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#5 Post by GustavoYz »

alice wrote:what's the meaning?
This?
rcrsn51 wrote:dd if=/dev/zero of=/dev/sda
Something like "Fill my sda drive with 0's".

sandlynx
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wiping a hdd with Puppy CD

#6 Post by sandlynx »

Something like "Fill my sda drive with 0's".
Question: Would this be the same as deleting a partition in GParted?
Filling the drive with zeros? Does this remove partitions too?

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rcrsn51
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Re: wiping a hdd with Puppy CD

#7 Post by rcrsn51 »

sandlynx wrote: Question: Would this be the same as deleting a partition in GParted?
No. Deleting a partition in Gparted just removes some information from the partition table in the MBR. The actual files and folders are still on the hard drive and could be recovered with the appropriate tools.
Filling the drive with zeros? Does this remove partitions too?
Yes. It would also erase the partition table. To use the drive again, you would have to build a new partition structure.

sandlynx
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Wiping hdds

#8 Post by sandlynx »

Thanks, that is vital info I can use in the future. :D

DPUP5520
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#9 Post by DPUP5520 »

Using dd is not an effective or efficient way to erase a drive securely or if you want the information to be unreadable and could still be recovered as rcrsn51said "using the appropriate tools". For secure wiping try the program I jus posted a few days ago, it wipes to dod 5220-22.M standards for drive sanitation.
http://www.murga-linux.com/puppy/viewto ... 723#517723
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=69651][b][i]PupRescue 2.5[/i][/b][/url]
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=72178][b][i]Puppy Crypt 528[/i][/b][/url]

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rcrsn51
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#10 Post by rcrsn51 »

DPUP5520 wrote:Using dd is not an effective or efficient way to erase a drive securely
Well.... That might be true if you are worried about the CIA getting its hands on the drive. But if that's the case, you would be better off taking a hammer to it.

From here:
An analysis by Wright et al. of recovery techniques, including magnetic force microscopy, also concludes that a single wipe is all that is required for modern drives.

DPUP5520
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#11 Post by DPUP5520 »

Ah well call me paranoid with a tin foil hat.
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=69651][b][i]PupRescue 2.5[/i][/b][/url]
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=72178][b][i]Puppy Crypt 528[/i][/b][/url]

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GustavoYz
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#12 Post by GustavoYz »

I was wondering if fill the drive with random data would help to those people worried about their ultra-private information...

DPUP5520
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#13 Post by DPUP5520 »

A common method used to counter data remanence is to overwrite the storage medium with new data. This is often called wiping or shredding a file or disk. Because such methods can often be implemented in software alone, and may be able to selectively target only part of a medium, it is a popular, low-cost option for some applications. Overwriting is generally an acceptable method of clearing, as long as the media is writable and not damaged.

The simplest overwrite technique writes the same data everywhere—often just a pattern of all zeros. At a minimum, this will prevent the data from being retrieved simply by reading from the medium again using standard system functions.

In an attempt to counter more advanced data recovery techniques, specific overwrite patterns and multiple passes have often been prescribed. These may be generic patterns intended to eradicate any trace signatures, for example, the seven-pass pattern: 0xF6, 0x00, 0xFF, random, 0x00, 0xFF, random; sometimes erroneously attributed to the US standard DOD_5220.22-M.

One challenge with an overwrite is that some areas of the disk may be inaccessible, due to media degradation or other errors. Software overwrite may also be problematic in high-security environments which require stronger controls on data commingling than can be provided by the software in use. The use of advanced storage technologies may also make file-based overwrite ineffective.
Not to start an argument or fight but your quote states that a single "wipe" is all that is required not a single pass, and as this quote shows a single pass using 0's is only effective against standard system functions not specific data recovery methods.
Yes GustavoYz that is why i refered to the tool I posted , you can configure the type of wipe you want to do which ex. three pass wipe, first pass zeros, second pass random character, third pass p character, verification pass. Quite effective for making sure anyone short of a government agency could not recover data from your hard drive.

Paranoid Puppy Out
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=69651][b][i]PupRescue 2.5[/i][/b][/url]
[url=http://www.murga-linux.com/puppy/viewtopic.php?t=72178][b][i]Puppy Crypt 528[/i][/b][/url]

sandlynx
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Great info

#14 Post by sandlynx »

I am learning all kinds of usable stuff here. Thanks.
Hoping the paranoia doesn't go with the knowledge. :lol:

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rcrsn51
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#15 Post by rcrsn51 »

In Gutmann's original article, he talks about extracting information from an erased hard drive by using techniques like Magnetic Force Microscopy. That means that you have to open the drive, remove the platters and analyse them with specialized equipment and trained technicians.

It's not like someone is going to pull your hard drive out of a dumpster, plug it into his own computer and extract your credit card number.

Even Gutmann has now backed away from his original erasure method because hard drive technology has changed so much in the interim.

Consider this scenario. You use dd to fill the drive with zeros using a single pass. You then read it back using dd and get nothing but zeros. You read it again and still get zeros. Why would you expect that someone else reading the drive would get the original data?

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GustavoYz
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#16 Post by GustavoYz »

For those who want to learn more about 'dd', I've this page in my bookmarks, perhaps somebody else find it interesting.
Regards.
PS.: Somebody said 'shred'?

MustardMan

#17 Post by MustardMan »

@GustavoYz : That is a fantastic guide you have there! It almost gives the impression "what can't you do with dd". My only complaint, you start to use commands and options I have only heard about, but don't know what they are or why.

For example, in nearly your first example... you use the option "conv" as such "conv=notrunc,noerror"

edit: OK, the options are explained (much) further down (in the follow-on post), but I am still quite unclear as to why they are used.

What do you do this for? You explain "dd" itself extremely well, but not why you use this (and sometimes other) options.

I stumbled upon this post looking for a way to erase a partition, but leave everything else intact (MBR, partition tables, etc).

Would I use "dd if=/dev/zero of=/dev/sda1" (for the first partition on SATA drive 1)?
or would I need the byte size and 'conv' options (with parameters)?

And would this wipe the partition completely blank, formatting and all, meaning I would need to reformat the partition (to FAT or NTFS for example)?

Thats OK if it does, I would just like to know what is going to happen when I press enter...

MustardMan

#18 Post by MustardMan »

In answer to my own question (I got bored and decided to try it ... what could possibly go wrong !!)

The command
"dd if=/dev/zero of=/dev/sda1 conv=notrunc"
wiped the partition (as expected). Then viewing the result with Gparted, it was unrecognised (answering my question). Using Gparted again to "format partition as" and all was good. A completely blank partition to fool around with...

Obviously the partition table only contains the start and end (and flags) of a partition, but not what it actually is.

(I don't know a great deal about the data formats on disks, I am more of a hardware guy)

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GustavoYz
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#19 Post by GustavoYz »

@MustardMan: Just saw your post now... :oops:

The "noerror" force the blocks with error to be copied anyway, with the error in it.
The "notrunc" part avoids the total replacement of the output by the input.
Obviously the partition table only contains the start and end (and flags) of a partition, but not what it actually is.
Exactly! Maybe, you'll find interesting this link.
Thus, you can blank a drive with dd, filling it with 0's. Also, you could fill it with random data before, in order of make the previosly stored data unreadable.
Puppy includes GParted so, I agree: what could possibly go wrong if you know what you're doing?

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Colonel Panic
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#20 Post by Colonel Panic »

Great thread, for which thanks. I followed this advice yesterday to wipe my hard drive. As far as I can see it works as well as DBan and I can still use Puppy while it's happening (post online etc.) :)

Cheers,

CP .
Last edited by Colonel Panic on Sat 07 Jul 2012, 17:23, edited 1 time in total.
Gigabyte M68MT-52P motherboard, AMD Athlon II X4 630, 5.8 GB of DDR3 RAM and a 250 GB Hitachi hard drive running Ubuntu 16.04.6, MX-19.2, Peppermint 10, PCLinuxOS 20.02, LXLE 18.04.3, Pardus 19.2, exGENT 200119, Bionic Pup 8.0 and Xenial CE 7.5 XL.

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