Wiping a USB drive.

On 2020-06-04 14:33, Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?

No.

If want to wipe it out, find a Linux machine and do a

#dd if=/dev/zero of=/dev/sd[x] where x is your drive.

/dev/zero will also discharge all your states too

You can always boot off a Live USB for Linux, but be careful you don't
wipe your hard drive. I unplug my drive when in
doubt.

https://spins.fedoraproject.org/xfce/

You could also look at Bleach Bit

On 05/06/2020 18.12, Andy Burns wrote:
Carlos E.R. wrote:

The charge is either there or not.

Or for QLC drives, it may be 1/4, 1/2 or 3/4 there ...


Interesting, I didn't know about those.

https://www.computerweekly.com/feature/What-is-QLC-flash-and-what-workloads-it-is-good-for


Still, once you write a cell, it forgets any previous state, there are
no residual charges that can be read.

--
Cheers, Carlos.

Carlos E.R. wrote:
On 05/06/2020 18.12, Andy Burns wrote:
Carlos E.R. wrote:

The charge is either there or not.

Or for QLC drives, it may be 1/4, 1/2 or 3/4 there ...


Interesting, I didn't know about those.

https://www.computerweekly.com/feature/What-is-QLC-flash-and-what-workloads-it-is-good-for



Still, once you write a cell, it forgets any previous state, there are
no residual charges that can be read.


As far as I know, it's in two steps.

Block erase first (drain the floating gates).

Write comes next (fill the floating gate to desired level).

The electron movement is via tunneling.

https://searchstorage.techtarget.com...nnel-injection

"Fowler-Nordheim tunneling involves electrons passing through a
barrier in the presence of a high electric field. During
write operation on NAND flash media, the electrons tunnel
through a thin dielectric material to change the electronic
charge of a floating gate associated with a memory cell."

"The process by which data is erased from NAND flash memory
is called Fowler-Nordheim tunnel releasing."

When the conditions for tunneling are removed, charge stays
on the floating gate for up to ten years or so. (No recent
information is available on that topic that I've seen.)

Paul

Paul wrote:
Frank Slootweg wrote:
Paul wrote:
Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?
http://www.chrysocome.net/downloads/dd-0.6beta3.zip

(Instructions)

http://www.chrysocome.net/dd

Administrator Command Prompt.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1M count=12345

Paul, no offense but can you please stop advising very dangerous tools
like 'dd' in cases where they absolutely not needed?

Yes, in your - very long - story you *do* say to be careful, but
that's like saying be careful when advising someone to use a handgun to
hammer in a nail.

The OP (Peter Jason) is not even aware (no critcism intended) of
something as simple as unticking the 'Ouick-Format' option when doing a
'Format', so why advising something as complex and dangerous as 'dd'?

So *please* next time you advise 'dd' (et al), look at the need, the
context and most of all the (knowledge of the) person asking for help.
Thank you.

[...]

Unticking Quick Format doesn't do a thing.

Untick Quick Format = clusters ignored entirely, $MFT or FAT written
Select Quick Format = clusters are *read* verified (no writes)

I assumed that it does the same thing as FORMAT does/did for
diskettes.

Anyway, my *point* is that the OP is very likely not experienced with
difficult/tricky/dangerous command-line commands.

I'm providing security advice, where you've put something
on media you regret, and seek to remove it. That's what
"dd" is for.

'dd' is just one of many choices and IMO a much too dangerous one in
the hands of an inexperienced user. Way too easy to erase the *wrong*
device. Even GG's advice is much less dangerous than 'dd'.

[...]

"dd" remains perfectly viable for the job,

I'm not saying 'dd' can not do the job, of course it can. I'm saying
it's too bloody dangerous in the hands of an inexperienced user. (Trust
me, in the past four decades, I've seen enough 'Oops! Wrong disk!'
(etc.) disasters from 'dd'.)

[...]

There are plenty of things you can regret doing on a computer.

Especially if you've the wrong - for you - tool in your hands.

Backups cover quite a few of them.

But, in most cases, you'll loose some work/data/time. Why take an
unneeded risk?

People don't ask these questions unless they have a reason.

But they don't ask for - too - dangerous tools.

Anyway, luckily the point is moot because the OP has used a much less
dangerous method for which he knows what it does and hence can consider
the (non-)risk.

Don't get me wrong, I - and many others - appreciate your many
contributions to these groups. They're mostly highly technical and
detailed. That's makes a you valued and respected contributor.

But this time I had to comment, because IMO you gave too dangerous
advice to an - in this respect- inexperienced user.

Take the feedback in its well-intended spirit.

Frank Slootweg wrote:
Paul wrote:
Frank Slootweg wrote:
Paul wrote:
Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?
http://www.chrysocome.net/downloads/dd-0.6beta3.zip

(Instructions)

http://www.chrysocome.net/dd

Administrator Command Prompt.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1M count=12345
Paul, no offense but can you please stop advising very dangerous tools
like 'dd' in cases where they absolutely not needed?

Yes, in your - very long - story you *do* say to be careful, but
that's like saying be careful when advising someone to use a handgun to
hammer in a nail.

The OP (Peter Jason) is not even aware (no critcism intended) of
something as simple as unticking the 'Ouick-Format' option when doing a
'Format', so why advising something as complex and dangerous as 'dd'?

So *please* next time you advise 'dd' (et al), look at the need, the
context and most of all the (knowledge of the) person asking for help.
Thank you.

[...]
Unticking Quick Format doesn't do a thing.

Untick Quick Format = clusters ignored entirely, $MFT or FAT written
Select Quick Format = clusters are *read* verified (no writes)

I assumed that it does the same thing as FORMAT does/did for
diskettes.

Anyway, my *point* is that the OP is very likely not experienced with
difficult/tricky/dangerous command-line commands.

I'm providing security advice, where you've put something
on media you regret, and seek to remove it. That's what
"dd" is for.

'dd' is just one of many choices and IMO a much too dangerous one in
the hands of an inexperienced user. Way too easy to erase the *wrong*
device. Even GG's advice is much less dangerous than 'dd'.

[...]

"dd" remains perfectly viable for the job,

I'm not saying 'dd' can not do the job, of course it can. I'm saying
it's too bloody dangerous in the hands of an inexperienced user. (Trust
me, in the past four decades, I've seen enough 'Oops! Wrong disk!'
(etc.) disasters from 'dd'.)

[...]

There are plenty of things you can regret doing on a computer.

Especially if you've the wrong - for you - tool in your hands.

Backups cover quite a few of them.

But, in most cases, you'll loose some work/data/time. Why take an
unneeded risk?

People don't ask these questions unless they have a reason.

But they don't ask for - too - dangerous tools.

Anyway, luckily the point is moot because the OP has used a much less
dangerous method for which he knows what it does and hence can consider
the (non-)risk.

Don't get me wrong, I - and many others - appreciate your many
contributions to these groups. They're mostly highly technical and
detailed. That's makes a you valued and respected contributor.

But this time I had to comment, because IMO you gave too dangerous
advice to an - in this respect- inexperienced user.

Take the feedback in its well-intended spirit.

I do test some of these things.

I tested SDelete by salting a volume, using it, and it failed.
There were multiple hits for the strings I expected
to be removed from the volume.

If you're a clever sort, you could always try booting
a computer (*with NO hard drives connected*) with DBAN DVD,
plug in the USB stick to be erased and use DBAN for the job.
If you can manage, select single pass with zeros is
good enough (and zeros make it easier to verify the
stick later, that it's clean). I've not tested DBAN
in a standalone fashion like that. I think I may have
tried deleting one hard drive once with it, and it
took longer than expected, implying the "one pass"
wasn't one pass after all.

The thing about "dd", is I know it will do only one pass,
so the impact on device life is predictable. You don't
want DBAN doing 35-pass Gutmann on the thing. That would
be totally unnecessary.

I don't know if anyone has made a "GUI" for dd, to make
it easier to use. Even ddrescue on Linux, I've never
seen a GUI offered for it, to help regular folks
do data recovery.

There will always be some utilities that are "DOS level",
but if you want their functions, you have to suck it up
and use them. Like the utility I used to do HPA on a
hard drive. Host Protected Area, to make the disk
seem artificially smaller. It speeds up things like
RAID testing, by making fake tiny volumes that rebuild
faster. It's stuff like that, if you try it, you'll have
hair loss before long. That might have been "hdparm".

There are lists of tools available. For example Heidi Eraser
is good, but I've never used it. I think it helps if
you're using it all along with a device. The development
interval for Heidi was quite large, while they worked out
issues with it. It wasn't a one day job, because they
wanted it to be thorough. That's an example of a "live"
eraser, where the rest of the file system should remain
standing. The approach of SDelete is different, in that
it doesn't focus on erasing a still-existing file. Instead
it tries to clean white space, including the "white spaces"
inside the $MFT. One reason for me not testing Heidi,
is looking at their forum told me what I needed to know
(not ripe at the time).

https://en.wikipedia.org/wiki/List_o...asing_software

I don't think I've had an accident yet with "dd".

Whereas in my Unix days, I had one or two "rm -Rf" accidents :-)
Likely a matter of familiarity breeding contempt
("what could go wrong?").

Paul

On Sun, 07 Jun 2020 18:25:32 -0400, Paul wrote:

I don't know if anyone has made a "GUI" for dd, to make
it easier to use. Even ddrescue on Linux, I've never
seen a GUI offered for it, to help regular folks
do data recovery.

ddrescue has had multiple GUIs for quite some time.

On 2020-06-07 15:25, Paul wrote:
WhereasÂ*inÂ*myÂ*UnixÂ*days,Â*IÂ*hadÂ*oneÂ*orÂ*two Â*"rmÂ*-Rf"Â*accidents :-)
LikelyÂ*aÂ*matterÂ*ofÂ*familiarityÂ*breedingÂ*cont empt
("whatÂ*couldÂ*goÂ*wrong?").

I had one of these too. I was up all night repairing
the boss' (worthless, no account) son's computer. I
finished just as everyone got there in the morning.
I told them I was tired and I was going home to sleep.
My boss told me I could not go home as it was my fault
(which it was). I shook my head and left.

Boss' sons ruin companies.

On 05/06/2020 01:11, Rene Lamontagne wrote:
On 2020-06-04 5:11 p.m., Sjouke Burry wrote:
On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

That's doing it the hard way,Â* Like having Sex standing up in a canoe.Â* :-)


Don't mock it until you try it.

Sjouke Burry wrote:
On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

You can use dd for this :-)

Since it's not running in "device" mode in this case,
it's safer. The most that can happen when used this way,
is you receive a "device full" error as the stop condition.

format K: === this writes a new FAT or $MFT. Important.
You want the file table to be empty when you start.
See the help for the appropriate syntax.

dd if=/dev/zero of=K:\big.bin bs=1048576 === make a file that is as big as
the partition. Good for NTFS.

del K:\big.bin # Remove the file when you're finished, leaving room now
# for new files to be added to the stick.

That won't work right for a FAT32 stick, but will
work as one command for an NTFS stick. With a FAT32 stick,
the sequence would look like this. I have a script I use for
preparing a certain volume, that uses this method.
To format the volume, I use the Ridgecrop fat32formatter.

fat32format.exe K: # Used for larger volumes that Windows won't touch.

dd if=/dev/zero of=K:\01.bin bs=1048576 count=4095 # Fill 4GB per time
dd if=/dev/zero of=K:\02.bin bs=1048576 count=4095
...

del K:\*.*

Paul

On 08/06/2020 04.12, T wrote:
On 2020-06-07 15:25, Paul wrote:
WhereasÂ*inÂ*myÂ*UnixÂ*days,Â*IÂ*hadÂ*oneÂ*orÂ*two Â*"rmÂ*-Rf"Â*accidents :-)
LikelyÂ*aÂ*matterÂ*ofÂ*familiarityÂ*breedingÂ*cont empt
("whatÂ*couldÂ*goÂ*wrong?").

I had one of these too.Â* I was up all night repairing
the boss' (worthless, no account) son's computer.Â* I
finished just as everyone got there in the morning.
I told them I was tired and I was going home to sleep.
My boss told me I could not go home as it was my fault
(which it was).Â* I shook my head and left.

Boss' sons ruin companies.

I don't remember having important accidents with dd, which I use a lot,
precisely because I'm aware that it is a dangerous command and I am
extra careful with it.

And once you are aware that it is dangerous, it is a very useful command.


--
Cheers, Carlos.

Paul wrote:
Frank Slootweg wrote:
[...]
Anyway, my *point* is that the OP is very likely not experienced with
difficult/tricky/dangerous command-line commands.
[...]
'dd' is just one of many choices and IMO a much too dangerous one in
the hands of an inexperienced user. Way too easy to erase the *wrong*
device. Even GG's advice is much less dangerous than 'dd'.
[...]
I'm not saying 'dd' can not do the job, of course it can. I'm saying
it's too bloody dangerous in the hands of an inexperienced user. (Trust
me, in the past four decades, I've seen enough 'Oops! Wrong disk!'
(etc.) disasters from 'dd'.)
[...]
Anyway, luckily the point is moot because the OP has used a much less
dangerous method for which he knows what it does and hence can consider
the (non-)risk.

Don't get me wrong, I - and many others - appreciate your many
contributions to these groups. They're mostly highly technical and
detailed. That's makes a you valued and respected contributor.

But this time I had to comment, because IMO you gave too dangerous
advice to an - in this respect- inexperienced user.

Take the feedback in its well-intended spirit.

I do test some of these things.

[Info on SDelete, DBAN, etc. deleted.]

You didn't comment on any of my comments and seem to dance around my
feedback/'criticism' instead of acknowledging/rejecting it, so I still
don't even know if you understood it.

Anyway, I see that you now have posted a *safe* method using 'dd',
i.e. format the USB stick and then use 'dd' to write a big zero-filled
file to it. (Your response was to Sjouke Burry. I hope the OP, Peter
Jason also sees it.)

On 2020-06-08 4:30 a.m., Dee Flowers wrote:
On 05/06/2020 01:11, Rene Lamontagne wrote:
On 2020-06-04 5:11 p.m., Sjouke Burry wrote:
On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

That's doing it the hard way,Â* Like having Sex standing up in a canoe.Â* :-)


Don't mock it until you try it.


No way! I'm 86 and scared of canoes. :-)

Rene

On 2020-06-08 05:05, Carlos E.R. wrote:
On 08/06/2020 04.12, T wrote:
On 2020-06-07 15:25, Paul wrote:
WhereasÂ*inÂ*myÂ*UnixÂ*days,Â*IÂ*hadÂ*oneÂ*orÂ*two Â*"rmÂ*-Rf"Â*accidents :-)
LikelyÂ*aÂ*matterÂ*ofÂ*familiarityÂ*breedingÂ*cont empt
("whatÂ*couldÂ*goÂ*wrong?").

I had one of these too.Â* I was up all night repairing
the boss' (worthless, no account) son's computer.Â* I
finished just as everyone got there in the morning.
I told them I was tired and I was going home to sleep.
My boss told me I could not go home as it was my fault
(which it was).Â* I shook my head and left.

Boss' sons ruin companies.

I don't remember having important accidents with dd, which I use a lot,
precisely because I'm aware that it is a dangerous command and I am
extra careful with it.

And once you are aware that it is dangerous, it is a very useful command.



If in doubt, unplug the devices at risk.

T wrote:
On 2020-06-08 05:05, Carlos E.R. wrote:
On 08/06/2020 04.12, T wrote:
On 2020-06-07 15:25, Paul wrote:
Whereas in my Unix days, I had one or two "rm -Rf" accidents :-)
Likely a matter of familiarity breeding contempt
("what could go wrong?").

I had one of these too. I was up all night repairing
the boss' (worthless, no account) son's computer. I
finished just as everyone got there in the morning.
I told them I was tired and I was going home to sleep.
My boss told me I could not go home as it was my fault
(which it was). I shook my head and left.

Boss' sons ruin companies.

I don't remember having important accidents with dd, which I use a
lot, precisely because I'm aware that it is a dangerous command and I
am extra careful with it.

And once you are aware that it is dangerous, it is a very useful command.



If in doubt, unplug the devices at risk.


For example, boot with a Linux LiveDVD, and have
only the disk needing erasure connected. On Linux
it might be:

sudo dd if=/dev/zero of=/dev/sda bs=1048576

*******

The Windows version of "dd.exe", has the all important command

dd --list

and that is chock-full of clues as to which disk is which.
You open diskmgmt.msc at the same time, and see the
"alignment" between the listing in the Command Prompt
window, and the information in Disk Management.

That's the single best feature (that the other platform
versions don't have).

Paul

On 2020-06-08 15:31, Paul wrote:
TheÂ*WindowsÂ*versionÂ*ofÂ*"dd.exe",Â*hasÂ*theÂ*al lÂ*importantÂ*command

Â*Â*Â*ddÂ*--list

Tried it in Fedora. Unrecognized command. Rats.

df and gparted are good too.