3 Questions ????

Post here if you just want to chat about... whatever.

Moderator: The Mod Squad

3 Questions ????

Postby c327 » Wed Jun 06, 2012 1:47 am

I have asked these two things and still have not received an answer or an explanation, or maybe I missed them ??

1) Is there any truth to this question "Some more stringent hard drive erasing standards forbid using data destruction software".

2) I wanted an explanation as to why when a mostly filled HDD is over written with zero's or what ever like when a HDD is erased in an attempt to cover up what was previously written on it, doesn't that over writting it self take up space on the HDD? If you had 100gb of data and then over write it with zero's, after your done don't you still have a HDD with 100gb of data, only this time one with 100gb of zero's ??

If that is true won't the HDD eventually get filled up with data of some kind on it??
Its like having a bag of 5 yellow sticks. I then paint them red but I still have 5 sticks in the bag.........
“Respect cannot be learned, purchased or acquired - it can only be earned” "Pay It Forward"
c327
Black Belt 4th Degree
Black Belt 4th Degree
 
Posts: 4390
Joined: Fri Feb 27, 2004 1:01 am
Location: Saint Augustine Florida

Postby evasive » Wed Jun 06, 2012 1:58 am

1.
http://pcsupport.about.com/od/toolsofth ... -drive.htm
Some more stringent hard drive erasing standards forbid using data destruction software, probably because of the possibility of user error and the variety of software and methods that exist. However, as long as your drive doesn't contain national security information, you should feel very comfortable using any one of these programs to erase a hard drive.

They essentially say the drive needs to be destructed physically if I read that one right.

2. All of the harddisk is essentially FREE SPACE. Only when you mark areas as having data in them in the File Allocation Table it will show up as being used. It's not sticks but cups. The only way to prevent a cup with something special in it (your data) being filled with air (zeroes) is keeping inventory (in the FAT) about what cups are filled. If your operating system has trouble reading the FAT for whatever reason (hardware failure, bug, virus) it can destroy data by itself.
We hate rut, but we fear change.
********************************
System error, strike any user to continue...
evasive
Mobo-fu Master
Mobo-fu Master
 
Posts: 37389
Joined: Sun May 06, 2001 12:01 am
Location: Netherlands

Postby Karlsweldt » Wed Jun 06, 2012 7:37 am

Refer to this earlier posting on 'hard drive wiping' about "filling" a drive.

This link to WIKI about hard disk architecture also is informative.

The state of a "zero" in digital language represents the 'off' status, and the state of a "one" in digital language represents the 'on' status.

The structure of the recording material on a floppy drive or hard drive can be influenced to orient the magnetic particles thousands of times over.. and each time, a new orientation can be created. The pattern of magnetic signals equate to the "zeros" and "ones" that are the basics of digital characters.
With solid-state drives, there is no magnetic reaction. Certain transistor types are intended to represent the "zero" state, and another type is intended to represent the "one" state. Each of those individual transistors has the ability to retain its last created status without requiring an input voltage or bias source. "Regular" type computer memory can retain its digital signatures only if having an input voltage or bias source.

The main reason a hard drive gets "filled" sooner than expected is that the browser may save all those Web page files, which are useless after you close the session.. plus all those temporary files gotten from updates and program patches. Most are no longer needed, so dump them.
F@H.. to solve mankind's maladies.. in our lifetimes!
Karlsweldt
Mobo-fu Master
Mobo-fu Master
 
Posts: 20671
Joined: Wed Nov 12, 2003 11:57 am
Location: 07438

Postby c327 » Wed Jun 06, 2012 11:46 pm

I'm going to give up asking this, possibly I am asking the question wrong?

All I want to know is "Some more stringent hard drive erasing standards forbid using data destruction software". Yes or no.

My question and interest is not in knowing about HDD erasing, I understand for the most part that true and complete erasing is not possible by John Q. Public and can be retrieved using special forensic software if needed.

My interest is in knowing if a HDD is over written with anything including zero's or cups or anything else doesn't that over writing in it self take up space on a HDD and in doing so doesn't all that over writing eventually fill up the HDD? Something is taking up space on the HDD be it what ever it is.

Erasing a HDD as one may think on the face of it isn't erasing anything, just the indexing to it or covering what is there up. My thinking is eventually the HDD after being filled with any anything, be it zero's or other data will eventually make the HDD unusable because there is no more space left.

On a magnetic tape when you erase the tape you are removing previously used space and not covering it up as one is doing with so called erasing a HDD.

Kind of beating this horse to death. Thanks for any additional comments, but Elvis has left the building on this subject.
“Respect cannot be learned, purchased or acquired - it can only be earned” "Pay It Forward"
c327
Black Belt 4th Degree
Black Belt 4th Degree
 
Posts: 4390
Joined: Fri Feb 27, 2004 1:01 am
Location: Saint Augustine Florida

Postby evasive » Thu Jun 07, 2012 1:04 am

When you buy your harddisk it is already completely filled, the basic structure for putting the bytes in there is already marked on the disk. This is because a harddisk is a DIGITAL medium. A casettetape is an ANALOG medium. Inherently different. If the question is: can I erase my harddisk look like a blank tape without the use of a degausser the answer is no: it has no erase head like your casette deck has.

Yes, some more stringent standards forbid the use of data destruction software because with the right tools, the right amount of time and the right people, you can pick up the remnants of previous written data at the edges of the tracks on the harddisk (there's always stray magnetism) despite zeroing it out even multiple times.
We hate rut, but we fear change.
********************************
System error, strike any user to continue...
evasive
Mobo-fu Master
Mobo-fu Master
 
Posts: 37389
Joined: Sun May 06, 2001 12:01 am
Location: Netherlands

Postby Karlsweldt » Thu Jun 07, 2012 8:06 am

Perhaps the gist to "erasing" a hard drive without "filling" it is not noted. You do not "add" data.. only realign the magnetic properties to reflect a different pattern.. essentially replacing the previous digital pattern signature with a new. Whether it be magnetic tape, a floppy disk or hard disk.. the process is nearly identical. Minute particles of magnetic material are held in a coating, not being able to move.. but their magnetic orientation can be altered. Once off the assembly line and tested, you cannot increase or add storage space. If data storage sectors go bad, yes you may loose some storage space. Those sectors are marked "bad" and cannot be used.

With any type hard drive, there are reserved sectors for the file access tables.. which must be retained. Plus the media descriptor in the master boot record (brand, capacity, model, heads/cylinders/sectors, format type). Some erasing software may destroy the contents of those reserved sectors, and access to the drive may be impossible.
F@H.. to solve mankind's maladies.. in our lifetimes!
Karlsweldt
Mobo-fu Master
Mobo-fu Master
 
Posts: 20671
Joined: Wed Nov 12, 2003 11:57 am
Location: 07438

Postby c327 » Thu Jun 07, 2012 11:06 pm

Thank you for taking the time to explain all this to me. I did learn a few things from it.
“Respect cannot be learned, purchased or acquired - it can only be earned” "Pay It Forward"
c327
Black Belt 4th Degree
Black Belt 4th Degree
 
Posts: 4390
Joined: Fri Feb 27, 2004 1:01 am
Location: Saint Augustine Florida

Postby evasive » Fri Jun 08, 2012 12:24 am

We are trying to answer your questions as good as we can, even though it can take some time before we actually understand the essence of the question. Thank you for your patience.
We hate rut, but we fear change.
********************************
System error, strike any user to continue...
evasive
Mobo-fu Master
Mobo-fu Master
 
Posts: 37389
Joined: Sun May 06, 2001 12:01 am
Location: Netherlands

Re: 3 Questions ????

Postby hunter1801 » Sat Jun 09, 2012 1:13 pm

Read the "edit" at the bottom of the page first if you don't want to read all the other stuff. I think I know what you are trying to ask in terms of things taking up space on an HD.

c327 wrote:Its like having a bag of 5 yellow sticks. I then paint them red but I still have 5 sticks in the bag.........


To me, this is the easiest way to look at it with this example:

Box = HD
Sticks = Amount of "space" on your HD
Paint = Data

You can always re-paint the sticks. If you want a different color, you just paint over whatever color is on it now, infinite times

Translates to you being able to write data on the "space" in your HD, infinite times. You can write over previous data(paint).

The sticks then become irrelevant in a way. The fact that there are sticks there doesn't mean anything. It just tells you how many different colors you can have. Sure it's full of sticks, but what COLOR they are is what matters. It's always full of sticks.

You can have whatever data you want on the 100gigs and can write over or remove any of the DATA on it. It isn't the SPACE that you are gaining/losing. The space is a constant 100g. You just tell your HD what those gigs are in terms of data.

You can always paint over some colors, or scratch away a layer to reveal a previous color. The previous color is ALWAYS there, just hidden under the new color.

Data is always on the disk, so it is technically always "full". You are just writing over previous data, but it is still there. You are basically just telling your HD not to look at that data any more.

In terms of your question regarding:
"Some more stringent hard drive erasing standards forbid using data destruction software".

I think the word "destruction" makes it a little unclear. There is a big difference between "erasing" and "destroying". If you are just erasing, then of course you wouldn't want to destroy the actual disk (which is the only true way to destroy data). So I would hope that destruction software would be forbidden, if all you want to do is erase. Would cause unnecessary damage.

Take a look at the Wiki regarding Destruction and data wiping:
http://en.wikipedia.org/wiki/Data_remanence#Destruction


EDIT: I think I know what you are getting at!! I actually remember making a thread about this a few years ago asking the same thing. It's a difficult question to word. Assuming I think I know what you are trying to ask.

Basically, you understand writing/writing over and all that. But by telling your HD to look at previous data as NEW data, that "telling it do this" should take up space right? Even if it's just a single 0 of information. Eventually, after you tell it to write over more stuff (erasing/writing over), you have "told" it to write over so much, that shouldn't all those "tells" take up space themselves?

Can't remember the answers that I got, but basically it boils down to the fact that you are not really taking up/using "space" on the HD I think.
hunter1801
Black Belt 1st Degree
Black Belt 1st Degree
 
Posts: 1958
Joined: Thu Feb 17, 2005 3:59 pm
Location: Orange County, California

Postby evasive » Sun Jun 10, 2012 11:51 pm

You can always re-paint the sticks. If you want a different color, you just paint over whatever color is on it now, infinite times


Yes, zero or one. That is the one we were looking for. Now to the question why some more stringent standards forbid using software: no matter how many times you repaint the sticks, there's always some area where the paint didn't fully cover.

With some pattern searching of residual magnetism they can recalculate the data at a given point to a certain level which is not equal to zero which is a risk some people do not want to take.
We hate rut, but we fear change.
********************************
System error, strike any user to continue...
evasive
Mobo-fu Master
Mobo-fu Master
 
Posts: 37389
Joined: Sun May 06, 2001 12:01 am
Location: Netherlands


Return to The Water Cooler

Who is online

Users browsing this forum: No registered users and 3 guests